Why Does Chemotherapy Make Your Hair Fall Out?

Scott 5
Maya asks: Why does Chemotherapy cause hair loss?

chemoMaya I love the question. It seems like once or twice a year I’m shaving my head to help raise money for cancer research and at every fundraiser, the question seems to come up- Why does the common treatment for cancer make body hair fall out? The answer is really pretty simple. It has to do with how different types of Chemotherapy target cancer cells. There are many different Chemotherapy drugs that work in different ways, so I will only speak in general terms regarding their side effects.

Most cells in the human body divide using a process called mitosis. This process has 5 phases (prophase, prometaphase, metaphase, anaphase, and telephase). It is preceded by interphase, and results in the cell dividing, called cytokinesis. When a cell reaches the end of its lifespan, it gets destroyed in a pre-programed process called apoptosis.

There are many types of cancer (over 200). All types are a result of the same problem, unregulated cell growth. Cells that divide more rapidly than apoptosis can regulate- effectively, too much mitosis. The result is excessive tissue, known as tumors. These tumors can be localized, or they can spread to surrounding areas through your lymphatic system or your blood stream.

Many Chemotherapy drugs work by interrupting mitosis. Most Chemotherapy cannot differentiate between abnormal cancer cells and normal healthy cells.  Because of this, cells that have high mitotic rates (multiply rapidly) can also be affected by Chemotherapy- cells like those found in your hair follicles, the lining of your mouth, stomach, and those found in your bone marrow. The result can be hair loss, decrease in production of white blood cells (thus why cancer patients are immune-suppressed), and inflammation of your digestive tract. In the end, chemotherapy will hopefully kill the cancer cells, and in the process, unfortunately, potentially cause hair loss. However, the healthy cells of your hair follicles will repair themselves, making your hair loss temporary, as is hopefully your cancer!

If you liked this article and the Bonus Facts below, you might also like:

Bonus Facts:

  • Why are there over 200 types of cancer? The answer is easy. There are over 200 different types of cells in the human body with all of these having the potential to become cancerous.
  • Normal healthy cells divide and die as they should. This leads one to ask, “how many times”? The average number of times normal healthy cells divide is known as the Hayflick Limit. It was named after Dr. Leonard Hayflick, who in 1965 noticed that cells divide a specific number of times before the division stops. The average was between 40-60. (There is one woman, though, who had tissue in her body that could divide apparently forever: The Woman with Immortal Cells)
  • If you took every cell in your body, at the time you were born, and accounted for all the cells they would produce and so on, multiplied that number by the average time it takes for those cells to die, you get what is known as the ultimate Hayflick limit. The maximum number of years you can theoretically live. That would be 120 years!
  • Christians of the world might find this particularly interesting as Genesis 6:3- Then the Lord said, “My Spirit will not contend with man forever, for he is mortal; his days will be a hundred and twenty years.” There are of course several other passages in the Bible related to the lifespan of humans. Psalms 90:10- “Our days may come to seventy years, or eighty, if our strength endures”. Psalms was of course a ballad to God and not a statement from God, so one could always point out that God would know better… It’s never a good idea to discuss politics and religion on a site that deals primarily in hard facts (the editor/overlord of this site usually clips away text that strays too far into opinionated aspects of politics, religion, or similar), but the topic is cancer and this is an interesting little tidbit. I think most people with cancer will at some point think about their own spirituality one way or the other and these are all interesting tidbits to discuss, so hopefully this won’t get clipped. :-)

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  1. Yash March 28, 2014 at 7:11 pm - Reply

    I never thought about that question before, glad i know the answer though. Keep up the good work, i learn something new from u guys almost everyday ;)

  2. Rebuttal July 29, 2014 at 7:20 am - Reply

    Not going to say that this proves anything (especially given the ages frequently given in biblical genealogy) but I found it interesting that the Ultimate Hayflick Limit matches Genesis 6:3

    Then the LORD said, “My Spirit will not contend with humans forever, for they are mortal; their days will be a hundred and twenty years.”

    • Rebuttal July 29, 2014 at 7:30 am - Reply

      And now I feel kind of silly. Wrote comment after reading emailed article, which did not include the Bonus Fact that I basically just repeated…

  3. MR T November 1, 2014 at 7:25 am - Reply

    Or, it’s your body’s way of telling you to stop poisoning it.

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