My roommate’s boots were extremely vicious today, causing these alarmingly large blisters to form on the back of her heels. But what allows boots, and other footwear, the right to ruin our days so easily with the formation of blisters? How do they even do it?

Let’s start with the basics: What’s a blister?

A blister is a layer of skin, more specifically one of the epidermis layers, that splits from the other layers of skin, allowing pus to squeeze between them.

Pus is the term used to describe the blood serum (without red blood cells and clotting factors) that usually consists of water, white blood cells, blood proteins in addition to a few other things (it can sometimes have bacteria, gross).

How do blisters form?

Footwear can cause blisters as a result of the friction between the two. This friction leads to the uppermost layers of the epidermis peeling away from some of the other layers, without falling off. This is is normally referred to as a Friction Blister (fitting, right?). Some footwear need to be broken into so that they don’t keep rubbing against your skin too often.

But there are things other than friction that can cause blisters too! These factors are:

  • Heat (sunburns can lead to blisters!)
  • Chemical reactions
  • Medical conditions (like cold sores or the chicken pox)

Don’t burst your bubble

Like most other things the body does, the formation of the blister is actually a good thing. If they remain intact, then the liquid in the blister will be reabsorbed after a new layer of skin has been formed underneath the blister and the old layer of skin will peel away completely.

If you pop the blister, however, it can lead  to the further infection of your skin since the unhealed area has been exposed. The raised layer of skin and the pus act as a protective shield against infections and allows your body to regenerate its new skin in peace.

However, if they hurt too much then you may need to let the pus out using sterile equipment, a sterilized needle or blade. It may hurt a lot when the pus in the blister has infectious particles or intrusive particles. If the pus is white/yellow, then it definitely contained infectious particles (this differs from healthy pus, which would be clear). If your skin around the blister is red or warm for a long time, that’s another sign of infection! If you think your blister is infected, it is best to get medical attention.

For the most part, the blisters are here to help us with our silly needs like uncomfortable (but fancy!) shoes or going out in the sun without sunscreen. They’ve got our backs, for sure, so let’s let them be.

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Breast Health

The month of October was Breast Cancer Awareness Month, so naturally I’m talking about Breast Health on the first of November. But since all diseases need year-long awareness, let me carry this one into November.

Who needs to monitor their breast health?

We all have breasts! That’s right, breasts for everyone! The only difference between female and male breasts is that male breasts lack specialized lobules, which are divisions of the breast required to aid in the production and excretion of milk. Apparently, Mother Nature thought men didn’t need to be able to produce milk, but I’m sure there are plenty of mothers out there that would argue otherwise.

Either way, there is only one difference between male and female breasts, which means that both women and men need to continuously monitor their breast health.

Why monitor breast health?

Breast cancer usually originates in the lobules of your breasts, which is probably a super great reason to keep an eye on them. And a scary one.

But I thought men don’t have lobules, so why do they get breast cancer? is probably what you’re thinking. Well, calm down, I’ll explain.

Men don’t have the lobules required to produce milk; they do, however, have lobules. The good ol’, regular lobules that give your breast its mass. So guys, girls, everyone, check your breasts regularly.

How do you do it though?

Here are some tips brought to us by the Canadian Breast Cancer Foundation:

  • Know how your breasts normally look and feel
  • Look and feel for changes, such as
    • Lumps
    • Thickening of the skin
    • Nipple changes and/or discharges
    • Redness of any part of the breast
    • Skin changes (rashes, colour, etc)
    • Dimpling or puckering of the skin or nipple
    • Swelling or pain in the breast area or under arm

Make sure to look and feel at each of these regions:

  • Each whole breast
  • Under and above each breast
  • Under both arms

If you’re ever worried, contact your family physician and set up an appointment. It is always better to be safe.

Next week we’ll look at the established Risk factors for Breast cancer to keep this ball of awareness rolling. Hope your Halloween night was great! Stay safe, lovelies! 🙂

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Whenever you run into something or take a bad fall, you’ll find a bruise in the place that hurts (so long as your skin didn’t tear!). But what causes bruising and is there a way to treat it?

What is bruising?

Bruises, also known as contusions or ecchymosis, are the localized pooling of blood outside of blood vessels. So a bruise is simply when your blood escapes your blood vessels in a tissue yet remains in a certain area.

Why do we bruise?

When a part of your body is struck, the impact causes your blood vessels (more specifically capillaries, though sometimes it’s venules) in that area to rupture. This releases blood cells close to the skin’s surface, which spread out under the skin giving it a reddish colour.

The Colour changes of a Bruise

  1. This reddish colour changes over the period of healing for a bruise. At the beginning, your bruise will be red because it will have an iron-oxygen complex.
  2. After a couple days, however, your bruise will change to a deep purple or a blue colour; this is because the oxygen will have been used up by the surrounding tissues, resulting in the loss of an iron-oxygen complex (which gave the blood its red colour).
  3. Then you bruise will slowly begin to heal; at around 5 days, your bruise may turn a green colour which is the result of hemoglobin, the protein found in our blood cells that contains iron to attract oxygen, breaking down in the blood cells that escaped.
  4. The final colour stage is a yellow or brown colour, where the body is reabsorbing the lost blood and in its last stretch of healing itself. This usually occurs after 9 or 10 days.

How to help your bruise heal

When your bruise is healing, the blood that remains in the blood vessels needs to clot to prevent the further loss of blood. To help with the clotting process, it is recommended that you rest the affected area to ensure that there is no additional stress on the tissue.

Also, apply something to cool the area, perhaps a bag of ice or an ice pack. By cooling the area, you help influence the blood vessels to constrict. By constricting, the blood vessels reduce blood flow which means that there will be less blood that is lost through the rupture. Icing the area will also help calm down any swelling that occurs, but make sure to only apply ice intermittently for a maximum duration of 20 minutes. For the first day, it’s recommended that you ice the bruise for 20 minutes, take a break from the cooling for 20 minutes, and then repeat.

Both of these methods will help prevent the spread of blood underneath the skin but outside of the blood vessels; in other words, it helps contain the blood that escaped from the blood vessel in one area.

If you don’t rest the tissue after its blood vessel ruptures, it is likely that blood will spread to other areas in the vicinity of the impacted area. This is why you will sometimes find that there is a new bruise near the original one a day or two later.

Your blood vessels will heal themselves over the roughly 9 day period and your skin should go back to normal; just remember, rest and ice up! If you don’t, it can take a lot longer for the tissue to heal.


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Background Info

You might have guessed already that melanin is one of the pigments that causes the colour of your hair, skin and eyes. But did you know that there are several types of melanin?

That’s right, the pigment we thought we knew so well is actually a family of pigments. Melanin is produced by melanocytes and is formed by aggregating several different component molecules together. The variability in the combinations of molecules results in the different types of melanin. The exact composition and structures of these melanin molecules are still being researched. But it is known that the metabolism of an amino acid, tyrosine, is required to produce melanin.

Everyone seems to have a relatively similar concentration of melanocytes in their bodies; however, the frequency at which the melanocytes are induced to produce melanin varies with different ethnicities and individuals due to an increase or decrease in the expression of the melanin-producing genes.

Benefits to having a lot of melanin

This dark pigment allows for the absorption of UV radiation, which prevents our cells from dying or becoming cancerous. Melanin helps protect our DNA from being damaged by UV rays. This aspect is extremely important as DNA encodes almost all of the parts of our body, with the exception of the bacteria that exist inside and our mitochondria (which we inherit from our moms). If even a single mutation were introduced into our genome, there’s a chance that it will result in a malfunctioning protein which can lead to the breakdown of different biological processes.

For cold-blooded animals, melanin also provides a way to absorb heat from sunlight.

Disadvantages to producing a lot of melanin

Having too much melanin can mean that even the smallest of stimuli, like a scratch, can induce the production of more melanin. This results in the formation of dark patches of skin at those areas.

Two types of melanin molecules will be involved in next week’s post about Hair Colour, so stay tuned!

Simon, J.D. 2013. John D. Simon. <>. August 22, 2013.

Taylor, S.C. 2003. The Advantages and Disadvantages of Having More Melanin in Your Skin. <>. August 22, 2013.


You get these little bumps on your skin when you’re cold or when you feel any strong emotion, such as fear. But how does our body produce these bumps and why? And why are they called goosebumps?

What are Goosebumps?

Goosebumps, also called cutis ancerina (which is the Latin translation of ‘the skin of the goose’), are the bumps that result from the erection of the hairs in our skin. It is an involuntary, or uncontrollable, response to cold temperatures or strong emotions.

How do we get them?

Last week, we talked about the four components of hair: the follicle, the shaft and the inner and outer sheaths. Each of  your hairs’ outer sheaths, which encompass the follicle and the inner sheath, are surrounded by fibrous layers that attach to smooth muscles known as erector pili. These muscle are stimulated by the autonomic nervous system, which is the division of our nervous system that works with our conscious effort. The involuntary muscle reflex that causes goosebumps is referred to as the pilomotor reflex.

When we’re in cold environments, our thermoreceptors signal to our brain that our body temperature is decreasing. This triggers the release of the hormone epinephrine (aka adrenaline), which targets these erector pili and causes them to contract. The contraction of these muscles causes our hairs to stand erect, which is also the cause of the bumps. In fact, erector pili literally translates to ‘a thing that erects hair’. See, scientific names aren’t that random at all!

If you recall from that first post I did about anxiety, epinephrine is also released when one feels anxious. When this feeling is so strong that it promotes the release of a large amount of epinephrine, it can trigger the contraction of the erector pili in our skin, causing goosebumps. The same can be said for when you’re frightened, since the body mechanisms for anxiety and fear are similar.

Okay… but why do we get goosebumps?

Goosebumps are more helpful to animals than they are for us. That being said, goosebumps aren’t a total waste of energy for our bodies.

It’s believed that the formation of goosebumps is a phenomenon that we inherited from our primal ancestors (for those who don’t believe in Evolution, their theory is still applicable to humans, don’t worry!).

You see, we’re hairy mammals and our hair allows us to retain some heat, somewhat like a natural blanket. There is also a layer of air that surrounds our bodies that can serve as an insulator for heat. Now, in the case of the evolutionist theory, our primal ancestors had a lot more hair than we do; thus, they had a better blanket and more warmth. So, when they were in cold environments, their hairs would stand up (much like ours). These raised hairs causes the insulating air layer to expand, allowing your body to retain more heat. In other words, the expansion of this layer of air due to your raised hairs decreases the amount of heat that you lose to the cold environment.

This theory can also be applied to us; however, we don’t have as much hair as the primal ancestors in the evolutionist theory. This means our ability to retain heat isn’t as efficient since the layer of insulating air wouldn’t be consistent due to the visible gaps between our hairs. But it can still be argued that goosebumps do try to help us stay warm!

A reason for animals to have goosebumps can also be related to their predator-prey relationships. If a prey were to experience goosebumps upon seeing their predator (due to fear usually), their fur would make them seem bigger than they actually are since the hairs would be standing out. This would give them a better chance at intimidating the predator, which in turn means that they have a slightly better chance at surviving the encounter.

Why are they called ‘Goosebumps’?

Have you ever plucked a goose? Or a duck? Or seen a frozen chicken in the grocery store with its skin still on? They all have bumps on their skin after having been plucked which look like the bumps we get! So that partially explains the name…

But why not call it ‘Duck-bumps’ or ‘Chicken-bumps’ (which would make sense in terms of fear)? It really all has to do with which bird has been domesticated at the time the term was coined. For the English, Germans, Polish, Russians and others, geese had been domesticated. For the Spanish, they coined the term ‘piel de gallina’ which translates to ‘the skin of the hen’. The Japanese term is torihada, which literally means ‘bird skin’. So really, the term varies for different languages and cultures.

So now you know what goosebumps are, how we get them, why we get them and why we call them goosebumps! And now you know that you can start calling them ‘duck-bumps’ without being wrong… That being said, I can’t promise you won’t get any strange looks.

Bubenik, G.A. 2003. Why do humans get “goosebumps” when they are cold, or under other circumstances? <>. August 15th, 2013.

Parker, A. 2010. Five things you probably didn’t know about your body. <>. August 15th, 2013.

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What’s up with hair? I mean, we see a bunch of commercials telling us how to take care of it and how to impress other people with it, but what is it made up of exactly?

What is hair?

Hair is actually composed of four components: the follicle, the shaft, the inner and outer sheaths.

The follicle

The follicle is a tube-like structure located in our skin and it has two components: the papilla and the bulb. The papilla contains itty bitty blood vessels (called capillaries) which provide nutrients to a bundle of cells. This bundle of cells is referred to as the bulb. The cells in the bulb actually divide every 23-72 hours, which is faster than any other cell in our body!

The shaft

The shaft is the part of the hair that is visible to us. It is composed of three layers dead, hard protein called keratin. The innermost layer is called the medulla and isn’t always present. The middle layer is the cortex, which makes up the majority of the shaft,  and the outermost layer is the cuticle. The cuticle is formed by overlapping scales, somewhat like a roof.

The inner and outer sheaths

The follicle is surrounded by two sheaths, an inner and outer sheath, which help protect and mold the hair. The inner sheath ends just above the opening of the sebaceous gland (Remember those? They provide oil [sebum] to our skin and are found in the dermis layer of our skin!) and follows the rest of the shaft. The outer sheath encloses both the inner sheath and the follicle, and it ends just below the sebaceous gland.

And that’s the structure of hair! The follicle is similar to the roots of a plant in that it provides the nutrients and allows the hair to stay in the skin. Around the follicle are two sheaths, which wrap around it to add more stability and strength. Finally, the part we see everyday is known as the shaft of the hair. That’s all to it.

In the next few weeks, we’ll explore different topics involving hair like goosebumps,  curly hair, the colour of hair, and greying hair! There will be a few random topics sprinkled in there too before things get too hairy.

Yes, that just happened.

Brannon, H. 2006. The biology of hair. <> August 7th, 2013.

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On a related note…

You’re quickly going to realize which side of the whole ‘intentional tanning‘ conversation I’m on, if you haven’t already.

Here’s a video I saw circulating around a week or two ago regarding melanoma. It’s more of a public service announcement than it is a biological explanation, but still worth a watch. Be forewarned though, it may tug at the heartstrings.

Take the message as a heads up, pay attention to yourself and get to know your skin.

Related Posts:
Ultraviolet Radiation

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It’s the middle of the summer, and a lot of people are either working on their tans or showing them off. But what causes us to tan? And what are some dangers to tanning?

How do we tan?

Tanning is a result of exposure to UVA rays (recall that they are the ultraviolet rays that have the longest wavelength and the least amount of energy).

These rays go to the lower layer of the epidermis, where cells called melanocytes are activated. These cells produce melanin, which is a dark pigment that helps with UV protection. The production of this pigment is what causes the darkening, or tanning, of the skin.

Darker-skinned people actually have deeper tans than lighter-skinned people due to their melanocytes producing more melanin.

Dangers of tanning

UVA rays can also penetrate its way to your blood vessels and nerves, which can in turn damage your immune system. This damage makes it harder to recover from diseases and can lead to melanoma (a serious type of skin cancer). This is why intentional tanning is somewhat controversial. In fact, using tanning beds before the age of 35 can increase your risk of melanoma by 75%.

So careful with your browning, ladies and gents!


The Skin Cancer Foundation. 2013. International Study Links Tanning Beds to Melanoma. <> August 01, 2013.



It’s that time again, when people are either getting brown or, unfortunately, red. There are a lot of people who get sunburns when they’re in the sun too much, but what is the actual cause of a sunburn? How should we treat them?

What is a sunburn?

A sunburn is characterized by a redness of your skin in addition to swelling and pain, and is the result of too much exposure to the sun.

What causes a sunburn?

Last week, we talked about ultraviolet radiation and its three subtypes. Of those three subtypes (A, B, C), it is UVB that causes sunburns.

The energy from these UVB rays (from the sun!) damages the cells at the surface of our skin, affecting our DNA. This results in the production of different proteins whose effects lead to our blood vessels in that area to widen, or dilate. 

This dilation of the blood vessels allow more blood cells to flow through them, which is why your skin gets redder. Your skin also gets warmer and begins to swell due to the enlargement of the vessels.

It usually takes between 4-6 hours for the proteins to be synthesized after overexposure, so inflammation and swelling won’t be observed until after that.

DNA damage can also lead to the destruction of a cell in contrast to the synthesis of different proteins; this is why your skin peels when you have a really bad sunburn.

Treatment and Prevention

As I mentioned last week, the way to prevent a sunburn and to protect yourself from UV radiation is to use sunscreen.

There are several different ways to treat a sunburn. To relieve pain, you try cooling down the sunburn with a cool bath or shower, or with aloe vera gel. The Aloe Vera gel will also help in moisturizing the dry skin.

And I feel like I say this all the time but stay hydrated! It’ll help.

You should always protect the sunburned skin too if you’re going to go outside. Usually the best way to do this is to cover it with clothing but if you can’t, then a thin layer of aloe vera with a top off of sunscreen spray will work!


And that’s the basics of a sunburn! Play safe and stay smart!

Ultraviolet Radiation

So it’s summer, the days are warm, and you want to have some fun in the sun! You are recommended, however, to limit the time you spend outside because of something called ‘ultraviolet radiation’. But what is ultraviolet radiation and why should we be concerned about it?

Ultraviolet Radiation

Ultraviolet (UV) radiation is one of the many forms of energy that exist, and it is emitted by the sun. It has shorter wavelengths than visible light, which allows it to appear invisible. Here’s a correlation you’re going to want to remember: the shorter the wavelength, the more energy the rays have.

There are three subtypes of UV radiation:


This form of radiation has the longest wavelength of the three, and it isn’t absorbed by the ozone layer at all. Therefore, 100% of these waves reach the Earth’s surface. This form of UV radiation is the least lethal of the three (longest wavelength, least energy).


This form of radiation has a wavelength that is between UVA and UVA. For the most part, these waves of energy are absorbed by the ozone layer; however, some of these rays are able to reach the Earth’s surface. This form of UV radiation is the one that everyone is worried about as it can be very harmful.


This of form of UV radiation has the shortest wavelength, and is therefore extremely lethal (shortest wavelength, most energy). Luckily, the ozone layer absorbs all of these rays, allowing us to be protected from them.


So, we know now that UVA and UVB rays reach us when we’re out in the sun. The perks of this is that UV radiation can provide us with Vitamin D, which can help strengthen our bones and teeth. These rays also help treat psoriasis and eczema, skin diseases where itchy patches form, by slowing the growth of skin cells! Also, a lot of people like tanning which can be attributed to exposure to UV radiation.


UV radiation can be worrying too because it can cause a variety of things including sunburns, skin cancer, and even cataracts. The amount of exposure to these rays determine how detrimental the result is.

Protect Yourself

In order to lessen the effects that UV radiation can have on you when you’re out and about, it’s suggested that you wear long, loose clothing. But, let’s be real here, that’s not going to happen when the temperature is around 20°C/68°F or higher. So your best bet is to stay in the shade when you can, and to pull out your sunscreen lotion and slather it on.

The lotion will have a particular Sun Protection Factor (SPF) associated with it. This number is indicative of how long you can be in the sun before you get a sunburn. Let me explain: if the SPF of the lotion is 30, then it will take you 30x longer than usual to get a sunburn. What does that mean? Well, if you normally get a sunburn after being in the sun for 15 minutes, then it will take you 450 minutes to get a sunburn if you use a lotion with an SPF of 30. It’s recommended that you use lotions with an SPF of at least 15. But if you know how long it takes you to burn and you know how long you’re going to be out in the sun, then some simple math could save you some pain.

And there you have it, UV radiation. Your skin is welcome. 

Upcoming posts: Sunburns and Tanning, oh my!



Eipstein, J.H., and Wang, S.Q. 2013. Understanding UVA and UVB. <> July 18, 2013.

Estes, P. 2013. What are UV rays? <> July 18, 2013.

World Health Organization. 2013. Health effects of UV radiation. <> July 18, 2013.