Staying healthy during chemotherapy means protecting your immune system, eating enough to maintain your strength, staying active when you can, and knowing which warning signs need immediate attention. Your body is under significant stress during treatment, and small, consistent habits make a real difference in how you feel and how well you tolerate each cycle.
Eat More Protein and Calories Than Usual
Chemotherapy increases your body’s demand for protein and calories. You need more than someone who isn’t in treatment, not less. Extra protein helps your body repair tissue, maintain muscle mass, and cope with side effects. Prioritize meat, fish, eggs, dairy, and plant-based proteins at every meal, and eat the protein-rich foods on your plate first.
Instead of three large meals, aim for five to six smaller meals and snacks throughout the day. This is easier on your stomach and helps you get enough calories even when your appetite is low. On days when solid food feels impossible, switch to smoothies, milkshakes, soups, or nutrition supplement drinks. A blender can be your best tool during treatment.
Side effects like mouth sores, dry mouth, sore throat, or changes in taste can make eating miserable. A few adjustments help:
- Mouth sores or sore throat: Skip citrus fruits, tomatoes, spicy foods, salty foods, and anything crunchy or sharp-edged. Stick to soft, cool, or room-temperature foods.
- Smell sensitivity: Avoid cooking strong-smelling foods like fish or brussels sprouts. Cold or no-cook foods (sandwiches, yogurt parfaits, protein bars, cereal with fruit) produce less odor.
- Dry mouth: Avoid alcohol, tobacco, and electronic cigarettes. Stay away from spicy, sour, or salty foods that irritate dry tissue.
A registered dietitian who specializes in oncology can tailor a plan to your specific treatment and side effects. Many cancer centers offer this service as part of your care.
Protect Yourself From Infection
Chemotherapy suppresses your white blood cells, leaving you vulnerable to infections that a healthy immune system would handle easily. Your white blood cell count typically drops to its lowest point 7 to 14 days after each treatment cycle, and that window is when you’re most at risk.
The basics matter more now than they ever have. Wash your hands frequently and thoroughly. Shower or bathe daily and use unscented lotion to keep your skin from cracking, since broken skin is an entry point for bacteria. Brush your teeth gently with a soft toothbrush. Try to avoid crowded places, and stay away from anyone who’s sick. Don’t share cups, utensils, or personal items like toothbrushes.
A few less obvious precautions: wear gloves when gardening or cleaning up after pets, since soil and animal waste carry bacteria and fungi your body can’t fight well right now. Keep household surfaces clean regularly.
Food Safety During Low Counts
When your immune system is compromised, foodborne bacteria that would normally cause a mild stomach bug can land you in the hospital. Certain foods carry higher risk and should be avoided entirely during treatment:
- Raw or undercooked meat, fish, shellfish, and eggs
- Deli and processed meats (salami, bologna, hot dogs, ham) unless heated until steaming
- Smoked seafood labeled as lox, kippered, or nova style
- Raw sprouts of any kind, including alfalfa, clover, and mung bean
- Unpasteurized products such as raw milk, soft cheeses, unpasteurized juice, cider, or honey
- Salad bars, buffets, and potlucks where food temperature and handling are unpredictable
At home, scrub raw fruits and vegetables thoroughly, cook meat and eggs all the way through, and use separate cutting boards and utensils for raw meat and produce.
Know the Temperature That Means Emergency
A fever of 100.4°F (38°C) or higher during chemotherapy requires an immediate call to your oncology team. This is not a “wait and see” situation. Fever during treatment can signal a serious infection called febrile neutropenia, which can escalate quickly when your white blood cell count is low. Keep a reliable thermometer at home and check your temperature any time you feel warm, chilled, or generally unwell.
Stay Hydrated, Especially After Treatment
Adequate fluid intake helps your kidneys flush out the chemotherapy drugs and their byproducts, reducing toxicity. Dehydration also worsens fatigue, nausea, and constipation, all of which are already common during treatment.
Specific hydration needs depend on your regimen. For certain drugs like cisplatin, Memorial Sloan Kettering recommends drinking at least four 8-ounce glasses of liquid between the end of your infusion and the next morning, then 8 to 12 glasses daily for the full week following treatment. Even if your regimen doesn’t carry the same kidney risks, consistent fluid intake throughout the day helps manage side effects. Water, broth, diluted juice, and electrolyte drinks all count.
Move Your Body When You Can
Exercise during chemotherapy sounds counterintuitive when you’re exhausted, but it’s one of the most effective tools for managing fatigue, anxiety, and depression during treatment. Research consistently shows that moderate-intensity exercise reduces cancer-related fatigue more effectively than rest alone. Low-intensity activity, by contrast, has little effect on fatigue.
The general target for cancer survivors is 150 minutes per week of moderate aerobic activity (walking, cycling, swimming) spread across at least three days, plus resistance training two or more days per week. That’s the ideal. In practice, any movement is better than none. If 30 minutes feels impossible, start with 10-minute walks. The most important guideline is simply to avoid being completely inactive.
Walking and stationary cycling are the most commonly studied and safest options during treatment. For resistance training, machines and free weights both work, but start with light weights and increase gradually. If you have concerns about lymphedema or specific surgical restrictions, ask your oncology team before starting a resistance program.
Manage Fatigue With Planning, Not Willpower
Cancer-related fatigue is different from normal tiredness. It doesn’t fully resolve with sleep, and it can fluctuate unpredictably across your treatment cycle. Rather than trying to push through, use energy conservation strategies: plan your most important activities for the times of day when you tend to feel best, delegate tasks when possible, prioritize what actually matters to you, and pace yourself rather than trying to do everything at once.
Sleep quality plays a significant role. Set consistent sleep and wake times, even on weekends. Keep your bedroom for sleep only, not for scrolling or watching TV in bed. Avoid caffeine, nicotine, and alcohol in the hours before bed. If you’re not sleeping, get up rather than lying awake, and return to bed when you feel drowsy. These cognitive-behavioral strategies have been shown to improve sleep quality and reduce fatigue in cancer patients.
Support Your Mental Health
The psychological toll of chemotherapy is real and measurable. Anxiety, depression, and a sense of lost control are common, and they affect your quality of life as much as physical side effects do. Even brief psychosocial support, just one or two sessions with a psycho-oncologist or social worker, is associated with meaningful reductions in distress that persist for months afterward. One study found improvements in depressive symptoms, mental quality of life, and overall well-being with small to medium effect sizes.
Psychosocial support also appears to protect your sense of self-efficacy, your belief in your ability to cope with what’s happening. Without support, that confidence tends to erode over the course of treatment. With even minimal intervention, it holds steady. Many cancer centers offer counseling, support groups, and social work services as part of treatment. These aren’t extras. They’re part of staying healthy through this process.
Vaccines and Timing
Live vaccines are off-limits during chemotherapy because your suppressed immune system could develop an actual infection from the weakened virus in the vaccine. Non-live vaccines (including flu shots and COVID-19 vaccines) are safe to receive, but timing matters. Your immune response will be weakest during the low point of your white blood cell cycle, typically 7 to 14 days after each treatment. If you need a vaccine during treatment, the best window is right before your next cycle, when your immune system has had the most time to recover.
Ideally, any outstanding immunizations should be completed before starting chemotherapy. After treatment ends, you’re generally no longer considered immunosuppressed about three months later, at which point your vaccine responses return to normal.