Cancer Treatment: The Side Effects of Chemotherapy

A man sits while undergoing chemotherapy cancer treatment as his wife looks on

A man sits while undergoing chemotherapy cancer treatment as his wife looks on. | John Moore/Getty Images

A cancer diagnosis, of any kind, is cause for alarm. Along with obesity-related maladies like heart disease and diabetes, cancer is one of the modern world’s most common causes of death. For that reason, we dedicate all kinds of resources to spreading awareness, inspect our bodies much more thoroughly than we used to, and generally take it as a very serious threat. Technology and modern medicine, however, have given us much better tools to fight it off.

That’s not to say that it’s still not scary or life-altering — but in many cases, cancer can be successfully treated and overcome. Yes, some cancers are deadlier than others, but we’ve made incredible progress over the years at increasing survival rates.

One of the most common forms of treatment is chemotherapy, the American Cancer Society reports. Chemo, as it’s commonly referred to, is an extremely rough process to experience. Essentially, you’re using a mixture of chemicals and drugs to destroy the cancer present in your body, or to at least shrink tumors and control the spread of the disease. You may not be completely cured, but life can be prolonged through these treatments.

Unfortunately, chemo also has some pretty nasty side effects. Because you’re dosing your body with a lot of chemicals and drugs, it’s not just the cancer cells that are being destroyed — often, your body’s natural functions and healthy tissues succumb to the treatment as well. Here is a short list of some of those side effects you should expect if you or a loved one is prescribed chemotherapy as treatment for cancer.

1. Mental cloudiness

A cancer patient rides to a doctor's appointment with his wife

Chemotherapy can cause mental fog. | John Moore/Getty Images

The mental cloudiness and loss of ability to focus both accompanying chemotherapy are often referred to as “chemo brain.” Basically, patients going through treatment find it hard to focus, formulate thoughts, or simply pay attention — their heads are in the proverbial cloud. This can make work or school difficult and can be quite debilitating for those who are trying to carry on with their normal life while going through chemo.

2. Fatigue

A breast cancer patient receives a chemotherapy drip

Cancer patients undergoing chemo are often tired. | Chris Hondros/Getty Images

In addition to the loss of focus, chemo will sap your energy, according to Mayo Clinic. Most people going through cancer treatment will experience fatigue, which means you can expect to be very tired and weak. There are a lot of factors that can impact fatigue levels, including your mental state, how much you’re eating, the type of cancer you have, and the treatment course you’re on. Be sure to get plenty of sleep, and eat enough to stay a step ahead.

3. Pain

A patient inspects his chemo drip in a hospital

Chemo can be quite uncomfortable. | Justin Sullivan/Getty Images

Unfortunately, chemotherapy is not a pleasant experience. Part of its unpleasantness is that it can be painful — which can actually make other side effects worse, like fatigue. The cancer itself can be a source of pain (invasive tumors, blood clots, etc.), and the treatment can cause nerve pain. This pain can come and go in flares, and may be chronic or acute.

4. Nerve problems

A nurse administering cancer treatment

Chemotherapy can cause problems with your nerves. | Photo by Justin Sullivan/Getty Images

On the topic of nerves, chemo can actually create some nerve and nervous system issues. You might experience numbness and pain in your extremities, and those pain flares that we mentioned previously are all a part of what’s going on. The nervous issues caused by treatment are called chemo-induced peripheral neuropathy, the ACS says, and can be treated by a doctor.

5. Gastrointestinal issues

An older cancer patient drinks water near a bathroom

Chemo can cause issues with your stomach. | Andrew Burton/Getty Images

As if the fatigue and pain weren’t enough, many patients experience a number of gastrointestinal issues while going through the treatment process. This manifests in a number of ways — vomiting, diarrhea, constipation, and even sores in your mouth and on your tongue are all fairly common.

6. Bruising and bleeding

A patient inspects their arm during treatment

Bruising is a common side effect. | Chris Hondros/Getty Images

If you’re going through chemo, you may find that your body is bruising and even bleeding much easier and more often than usual. This is common, and while it’s unpleasant, is something to be expected. Your bone marrow — where blood cells are produced — can be affected by the chemo treatment. This makes it more difficult for your blood to clot, and disrupts your body’s natural repair mechanisms.

7. Libido and fertility changes

Buttons with the words "cancer sucks" are seen on display in the gift shop

Changes in your libido are to be expected. | Justin Sullivan/Getty Images

Finally, experiencing a drop in your sex drive is another common side effect of chemotherapy. Not only that, but it is possible that your fertility will be impacted during treatment. This can depend on the specific drugs being used in your treatment and is something that you should discuss with your doctor should it be a concern.