Hair loss (alopecia)

Radiotherapy and chemotherapy cause hair loss and hair loss because they damage the cells in the follicles responsible for their growth.


Radiation therapy only causes the hair on which the rays fall. The irradiation of a lung tumor, for example, will only cause the chest hairs included in the field to fall; the hair or hair on the abdomen will never fall out unless the patient receives chemotherapy at the same time. The intensity of hair loss, which occurs when the scalp is included in the irradiation field, depends on the dose and method of treatment.

Usually, the hair grows back a few months after the end of radiation therapy. In about a year, the growth may have been almost complete. The texture and color of the new yarns may differ from the previous ones. When radiation doses are very high, the fall can be irreversible (a rarer phenomenon).


Not all chemotherapy drugs cause hair loss. Some schemes cause shedding of all body hair, while others can save them or lead to partial loss. When hair loss occurs, it usually appears two or three weeks after treatment begins and tends to progress with repeated cycles. The amount of hair lost will depend on the drugs used, the doses and the intervals of administration.

The hair starts to grow again one to two months after the treatment ends, returning to normal in six months to a year. To deal with hair loss it is convenient:

  • Cut your hair short before starting treatment. This way, you will avoid more radical changes in appearance when the hair falls out and will recover the previous image more quickly when they grow.
  • Use softer brushes and less aggressive shampoos, such as those indicated for children.
  • If you plan on wearing a wig, buy it while you still have hair, so you can choose one of the same color.
  • Avoid applying chemicals that can harm the scalp.
  • Do not use a very hot dryer.
  • Wear sunscreen, hats, caps and scarves to protect your scalp.
  • If you are going to shave your head, do it with an electric razor, never with a razor blade.
  • After treatment, avoid straightening or coloring your hair until the new strands have reached about 5 to 6 cm.

If the concern with alopecia is very high, the doctor may advise the patient about the use of Elasto-gel, a cap capable of cooling the scalp during chemotherapy, in order to reduce hair loss during treatment.