Chemo side effects: What should I expect and how to cope?

Medically reviewed by Kristianne Hannemann, PharmD. Last updated on June 2, 2025.

Official Answer by Drugs.com

Chemotherapy is a drug treatment used to kill fast-growing cancer cells in your body. While chemotherapy is an effective treatment for many types of cancer, it can also damage healthy cells that divide quickly, such as those in your hair follicles, digestive tract, and bone marrow. This widespread effect on healthy tissue is what causes the various side effects associated with chemotherapy treatment.

Side effects and their severity vary significantly from patient to patient and depend on factors such as the specific drugs used, dosage, duration of treatment, and individual patient characteristics. Side effects differ depending on the regimen, such as FOLFOX, R-CHOP, or FOLFIRINOX, with some combinations being associated with more frequent and severe side effects than others.

What Are the Most Common Chemotherapy Side Effects?

While each patient may experience different side effects from chemotherapy, there are several side effects that affect many patients. Some of the most common side effects from chemotherapy include:

Fatigue
Nausea and vomiting
Hair loss
Mouth sores
Appetite changes
Weight loss
Diarrhea or constipation

Below, we will review each side effect in more detail.

Fatigue

Fatigue is one of the most common and debilitating side effects of chemotherapy, affecting daily activities. It often becomes worse over time. This type of fatigue is different from normal tiredness and may not improve with rest. Fatigue can be caused by anemia, poor nutrition, dehydration, or the toxic substances produced when cancer cells break down and die. In one study of patients receiving their first cycle of chemotherapy, fatigue was identified as one of the most frequent side effects experienced.

Nausea and Vomiting

Nausea and vomiting are among the most common chemotherapy side effects, though they are usually manageable with antiemetic medications. These symptoms typically begin a few minutes to hours after treatment and may last about 24 hours, though delayed nausea can occur more than 24 hours later. Some chemotherapy drugs are more likely to cause nausea and vomiting than others, and combination regimens or high-dose treatments increase this risk.

Hair Loss

Hair loss is a well-known side effect that occurs because chemotherapy damages hair follicles. Not all chemotherapy drugs cause hair loss, but it typically begins 2-3 weeks after treatment starts. The extent of hair loss varies by drug type and dose. For example, complete alopecia can be seen with almost all anthracycline-based regimens, while CMF regimens may cause only partial hair loss. In most cases, hair grows back after treatment ends, though some drugs like docetaxel can occasionally cause permanent hair loss.

Mouth Sores (Mucositis)

Mucositis involves inflammation of the mucous membranes lining the mouth and throat, making eating and speaking painful. This occurs because chemotherapy damages rapidly dividing cells in these protective linings. The condition can lead to painful ulcers, bleeding, and increased infection risk.

Appetite Changes and Weight Loss

Many patients experience significant appetite changes during chemotherapy treatment. This can result from nausea and vomiting, fatigue, taste changes, or the buildup of waste products as cancer cells die. Some chemotherapy drugs temporarily alter taste and smell, making food less appetizing and potentially leading to malnutrition and weight loss.

Diarrhea or Constipation

Gastrointestinal effects are common, with chemotherapy drugs affecting cells lining the digestive tract. Diarrhea often occurs soon after treatment begins and may continue for up to two weeks. Conversely, several chemotherapy and supportive drugs can cause constipation. These effects vary depending on the specific drugs used in the regimen.

Blood-Related Side Effects

Chemotherapy commonly affects blood cell production because blood cells are among the fastest-dividing cells in the body. Blood cells are made in the bone marrow, which is the spongy tissue found inside the hollow bones. The bone marrow produces three main types of blood cells: red blood cells that carry oxygen around the body, white blood cells that fight infections, and platelets that help blood clot and prevent bleeding. Since these rapidly dividing cells can be damaged by chemotherapy, blood cell counts often drop during treatment, leading to complications such as anemia, increased infection risk, and bleeding problems.

Anemia

Anemia, characterized by low red blood cell counts, causes fatigue and shortness of breath. This condition affects the body's ability to carry oxygen effectively, contributing to the overall weakness experienced during treatment.

Neutropenia

Neutropenia involves dangerously low white blood cell counts, significantly raising infection risk. This is particularly notable with certain regimens like EPOCH and CHOP, where myelosuppression is a common concern. Severe neutropenia may result in hospitalization and can be life-threatening if infections develop.

Thrombocytopenia

Thrombocytopenia, or having low platelet counts, increases bleeding and bruising risk. In studies of chemotherapy regimens, rates of thrombocytopenia varied significantly. For example, DHAP regimen showed 92% incidence while CHOP showed 25% in one study. The bleeding risk associated with thrombocytopenia can lead to fear and anxiety in patients.

Monitoring blood counts is routine during regimens like R-CHOP, FOLFIRINOX, or CAPOX, as these treatments commonly affect bone marrow function and blood cell production.

Nerve, Skin, and Sensory Effects

Chemotherapy can affect the nervous system, skin, and sensory organs because these systems contain cells that are sensitive to the toxic effects of cancer-fighting drugs. The peripheral nervous system, which includes nerves outside the brain and spinal cord, can be damaged by certain chemotherapy agents, leading to numbness, tingling, and pain. Similarly, the skin and its associated structures like hair follicles and nails are particularly vulnerable because skin cells divide rapidly to maintain the protective barrier of the body. Sensory changes, including alterations in taste, smell, and touch sensitivity, can occur when chemotherapy affects nerve endings and sensory receptors. These side effects can significantly impact daily activities and quality of life, ranging from difficulty with fine motor tasks due to neuropathy to increased vulnerability to sun damage and changes in appearance.

Emotional, Cognitive, and Long-Term Effects

Beyond the physical side effects of chemotherapy, cancer treatment can significantly impact mental and emotional well-being, creating challenges that extend far beyond the treatment period. Chemotherapy affects the brain and nervous system because these cancer-fighting drugs can cross the blood-brain barrier and damage healthy brain cells, leading to inflammation and changes in brain structure and function. These effects, commonly referred to as "chemo brain" or "chemo fog," can include difficulties with memory, concentration, attention, and processing speed. Additionally, the psychological stress of cancer diagnosis combined with the direct neurological effects of treatment can lead to mood changes, anxiety, depression, and other emotional challenges.

Chemo Brain

Chemotherapy-induced cognitive impairment, commonly called "chemo brain" or "chemo fog," affects memory, concentration, and processing speed. Studies indicate that 15-75% of patients experience cognitive impairment after chemotherapy, with 17-35% suffering long-term effects. These symptoms can persist long after treatment completion and significantly impact quality of life.

Mood Changes

Anxiety and depression are common during chemotherapy treatment, resulting from both the psychological stress of cancer diagnosis and the direct effects of treatment on brain chemistry. The combination of physical symptoms, treatment burden, and uncertainty about the future contributes to emotional distress.

Fertility Issues

Chemotherapy can affect reproductive function, potentially causing temporary or permanent fertility problems. The impact varies depending on the specific drugs used, dosage, and patient age. Some effects may be reversible after treatment, while others may be permanent.

Organ Toxicity

Certain chemotherapy drugs can cause damage to specific organs. For example, doxorubicin is associated with heart toxicity, while bleomycin can affect lung function. Regular monitoring helps detect these effects early.

Second Cancers

Though rare, some chemotherapy agents can increase the risk of developing secondary cancers years after treatment. The risk varies by drug type and treatment intensity.

How to Manage Chemotherapy Side Effects

While chemotherapy side effects can be challenging, the good news is that many effective strategies exist to prevent, minimize, and manage these symptoms. Management approaches include both pharmacological interventions, such as medications given alongside chemotherapy to protect healthy cells, and non-pharmacological interventions like acupressure, music therapy, and other complementary techniques. Your healthcare provider can advise you on specific strategies tailored to your treatment regimen and individual needs.

Fatigue: Prioritize rest, light activity, and hydration.
Nausea: Use prescribed antiemetics (e.g., ondansetron); eat small meals.
Hair Loss: Consider scalp cooling or head coverings.
Mouth Sores: Rinse with saltwater; avoid spicy or acidic foods.
Diarrhea/Constipation: Stay hydrated, get enough dietary fiber, and consider medications like loperamide after checking with your healthcare provider.
Neuropathy: Avoid cold; discuss dose adjustments if severe.

Conclusion

Chemotherapy side effects can feel overwhelming, but understanding what to expect and having effective management strategies can significantly improve your treatment experience and quality of life. Remember that side effects vary greatly from person to person, and many patients experience fewer or milder symptoms than they initially feared.

The most important factor in successfully managing chemotherapy side effects is maintaining open, honest communication with your healthcare team. Don't hesitate to report any symptoms, no matter how minor they may seem, as early intervention often prevents more serious complications.

References

Altun, İ., & Sonkaya, A. (2018). The Most Common Side Effects Experienced by Patients Were Receiving First Cycle of Chemotherapy. Iranian journal of public health, 47(8), 1218–1219. PMCID: PMC6123577 PMID: 30186799
American Cancer Society. 2025. Chemotherapy Side Effects. Accessed on June 2, 2025 at https://www.cancer.org/cancer/managing-cancer/treatment-types/chemotherapy/chemotherapy-side-effects.html
Canadian Cancer Society. Side effects of chemotherapy. Accessed on June 2, 2025 at https://cancer.ca/en/treatments/treatment-types/chemotherapy/side-effects-of-chemotherapy
Crawford, J., et. al. 2024. The impact of myelosuppression on quality of life of patients treated with chemotherapy. Future oncology (London, England), 20(21), 1515–1530. https://doi.org/10.2217/fon-2023-0513
Das, A., et. al. 2020. An Overview on Chemotherapy-induced Cognitive Impairment and Potential Role of Antidepressants. Current neuropharmacology, 18(9), 838–851. https://doi.org/10.2174/1570159X18666200221113842
Kato, N., et. al. 2024. Risk Factors for Thrombocytopenia Induced by Capecitabine Plus Oxaliplatin Therapy in Patients With Colorectal Cancer. In vivo (Athens, Greece), 38(3), 1243–1252. https://doi.org/10.21873/invivo.13561
Kerckhove, N., et. al. 2017. Long-Term Effects, Pathophysiological Mechanisms, and Risk Factors of Chemotherapy-Induced Peripheral Neuropathies: A Comprehensive Literature Review. Frontiers in pharmacology, 8, 86. https://doi.org/10.3389/fphar.2017.00086
Kerkmann, A., et. al. 2024. Chemotherapy-induced cognitive impairment and its long-term development in patients with breast cancer: results from the observational CICARO study, The Oncologist, Volume 30, Issue 2, February 2025, oyae268, https://doi.org/10.1093/oncolo/oyae268
Lu, R., Lin, Q., et. al. 2020. Chemotherapy-induced thrombocytopenia and platelet transfusion in patients with diffuse large B-cell lymphoma. Translational cancer research, 9(3), 1640–1651. https://doi.org/10.21037/tcr.2020.01.64
Murillo, L. C., et. al. 2023. An update on neurobiological mechanisms involved in the development of chemotherapy-induced cognitive impairment (CICI). Toxicology reports, 10, 544–553. https://doi.org/10.1016/j.toxrep.2023.04.015
National Cancer Institute. 2025. Nausea and Vomiting Related to Cancer Treatment (PDQ®)–Health Professional Version. Accessed on June 2, 2025 at https://www.cancer.gov/about-cancer/treatment/side-effects/nausea/nausea-hp-pdq
Okusaka, T., et. al. 2014. Phase II study of FOLFIRINOX for chemotherapy-naïve Japanese patients with metastatic pancreatic cancer. Cancer science, 105(10), 1321–1326. https://doi.org/10.1111/cas.12501
Partridge, A. H., et. al. 2001.Side Effects of Chemotherapy and Combined Chemohormonal Therapy in Women With Early-Stage Breast Cancer, JNCI Monographs, Volume 2001, Issue 30, Pages 135–142, https://doi.org/10.1093/oxfordjournals.jncimonographs.a003451
Sibaud V. 2022. Anticancer treatments and photosensitivity. Journal of the European Academy of Dermatology and Venereology : JEADV, 36 Suppl 6(Suppl 6), 51–58. https://doi.org/10.1111/jdv.18200
Starobova, H., et. al. 2017. Pathophysiology of Chemotherapy-Induced Peripheral Neuropathy. Frontiers in molecular neuroscience, 10, 174. https://doi.org/10.3389/fnmol.2017.00174
Zhang, M. C., et. al. 2023. Genetic subtype-guided immunochemotherapy in diffuse large B cell lymphoma: The randomized GUIDANCE-01 trial. Cancer cell, 41(10), 1705–1716.e5. https://doi.org/10.1016/j.ccell.2023.09.004

How soon will my hair grow back after chemotherapy?

After finishing chemotherapy, some may notice fine, soft hair appearing as early as 3 to 6 weeks after treatment ends. It can take several months for your hair to return to its previous length and thickness, and there may be temporary changes in texture or color.

Radiation vs. Chemo: Which cancer treatment is right for you?

Chemotherapy treats cancer throughout the body, while radiation targets specific areas. Each approach has unique benefits depending on the type and stage of cancer, as well as your overall health.

Will I lose my hair during chemotherapy treatment?

Chemotherapy-induced hair loss is common and usually temporary, caused by the drugs targeting rapidly dividing hair follicle cells. Hair loss typically starts a few weeks after treatment begins and regrows a few months after it ends.