Why Does Hair Fall Out During Chemotherapy?

Chemotherapy

To understand why chemotherapy causes hair to fall out, you must first know how chemotherapy works. Chemotherapy is a common cancer treatment that is used to alter cancer cells so that they no longer grow uncontrollably; in the process, it also kills the cell. Because chemotherapy can harm both cancer cells and healthy body cells, it is given through cycles. This allows time for body cells to recover and targets cancer cells when they are most vulnerable.

Cell Growth

Chemotherapy targets any cell in the body that is growing and multiplying at an increased rate. This is because cancer mutates cells in such a way that they begin to grow and multiply at a dramatically different rate than other cells in the body. As we grow into adults, cells are constantly dividing to help the body grow and develop. Once adulthood is reached, most of these cells become dormant and stop dividing. Unfortunately, some cells, such as the cells that grow and produce hair, continue to grow and divide at an increased rate to replenish the natural growth and loss of your hair.

Hair Matrix

Hair growth starts in an area of your hair follicles called your hair matrix. In this area, epithelial cells constantly are dividing to create the fibers of your hair. These epithelial cells are one of the fastest growing cell populations in your entire body. When chemotherapy drugs enter your system, they cannot tell the difference between a cancer cell and a healthy body cell. The only thing it can recognize is how fast the cell is dividing. Because of this, not only do the chemotherapy drugs attack cancer cells, but they mistake epithelial hair cells as cancer cells as well. In the process, they kill your epithelial hair cells, causing your hair to fall out.

Recovery

Unlike cancer cells, your epithelial hair cells can recover after a series of chemotherapy. According to the Mayo Clinic, it can take between 4 and 6 weeks after your last series of chemotherapy for hair growth to continue. Your hair may also look and feel different for the first few months, but regular hair growth will return after that point.

References

• Cancer Help
• Mayo Clinic