Poor appetite and nausea
Nausea and poor appetite are among the most common and most draining side effects of leukemia treatment. The good news is that today there are effective medicines and simple everyday techniques to prevent them. This topic explains the types of nausea, how the medicines work, tips that make eating easier and when to call urgently.
01Short answer
02Simple explanation
Nausea happens when the “vomiting centre” in the brain is triggered by chemotherapy, some other medicines, infection, constipation or anxiety. The causes can differ, so it is important to tell your team.
Acute nausea occurs in the first 24 hours after a medicine; delayed nausea comes in the following days. Nausea that starts before treatment because of past experience is called anticipatory nausea.
Anti-sickness medicines (antiemetics) are better at “preventing the fire” than “putting it out”. That is why you should take them without waiting for nausea, as prescribed.
Poor appetite can be caused by the illness, medicines, taste changes, mouth sores and tiredness. It is not “weak willpower”; it is a temporary reaction of the body.
The goal is not perfect eating every day. Some days will be hard. What matters most is getting fluids and, when you can, energy and protein.
03Scientific explanation
Choosing medicines: according to the 2020 ASCO and 2023 MASCC/ESMO guidelines, anti-sickness medicines are chosen according to the emetic risk of each treatment. For high-risk treatment, medicines from different groups are combined: 5-HT3 blockers (such as ondansetron), NK1 blockers (such as aprepitant), dexamethasone and olanzapine. Your hematologist decides the combination and how long to take it.
Anticipatory nausea: according to NCI, the best prevention is good nausea control from the very first cycle. If it has already developed, relaxation, breathing exercises and other behavioural techniques can help.
Ginger: according to the US National Center for Complementary and Integrative Health (NCCIH), some studies suggest ginger may slightly reduce chemotherapy-related nausea, but the results are mixed. It does not replace medicines; discuss ginger capsules and supplements with your team first.
Appetite and the mouth: the 2020 ASCO guideline suggests dietitian advice for significant loss of appetite and weight; in some cases a doctor may consider appetite-boosting medicines for a short time. The 2020 MASCC/ISOO guidelines advise regular mouth care to help prevent mouth sores.
04What happens in the body?
What helps with nausea?
Eat little and often; a completely empty stomach can make nausea worse. Dry, plain foods such as rusks, crackers, rice, mashed potato and boiled chicken are easier to keep down. Avoid greasy, spicy, very sweet and strong-smelling food. Sit upright for 30–60 minutes after eating, let fresh air into the room and wear loose clothes.
Fluids and vomiting
Drink between meals rather than with them, in small sips. Water, weak tea, kompot, diluted juice or clear broth are good choices. After vomiting, rinse your mouth and rest for a while, then start sipping again. If you cannot keep fluids down, do not wait; call your team.
When appetite is poor
Eat by the clock, small portions every 2–3 hours, without waiting to feel hungry. Have your most filling meal when your appetite is best (often in the morning). Enrich dishes with energy: butter in porridge, yogurt or egg in soup, cheese in mashed potato. Milk or yogurt drinks and nutritional drinks recommended by a dietitian can help.
Taste and smell changes
During treatment food may taste metallic, bitter or “of nothing”. If you have a metallic taste, use plastic cutlery. If you have no mouth sores, lemon, pomegranate sauce or spices can liven up the taste. Cold or room-temperature dishes give off less smell. Rinsing your mouth before eating freshens the taste.
When you have mouth sores
Choose soft, moist, room-temperature foods: porridge, mashed potato, eggs, cottage cheese, yogurt, soup. Avoid sour, salty, spicy, hard and very hot foods. Use a soft toothbrush and an alcohol-free mouthwash. If pain stops you eating, tell your team; there are painkillers and special mouth rinses.
When to call straight away
If you cannot keep fluids or medicines down; vomiting does not stop for several hours; there is blood or material like coffee grounds in your vomit; you have severe abdominal pain, dizziness or pass very little urine; you have a fever; or poor appetite means you have eaten almost nothing for a day or two.
05Four steps to prevent nausea
Medicines and everyday techniques work better together.
06The problem and what may help
| Problem | What may help | When to tell your team |
|---|---|---|
| Nausea | Medicine on time, small portions, dry foods, fresh air | If the medicine is not helping |
| Vomiting | Sipping fluids, rinsing the mouth, rest | If fluids or medicines will not stay down: straight away |
| Poor appetite | Eating by the clock, enriching dishes, nutritional drinks | If your weight is dropping quickly |
| Taste changes | Plastic cutlery, cold dishes, spices (if no sores) | If you are refusing food altogether |
| Mouth sores | Soft, moist, room-temperature food; mouth care | If pain stops you eating and drinking |
| Constipation | Fluids, moving about, fibre (if your team agrees) | If you have not opened your bowels for several days |
* This table is general information. Which medicine to take, and when, is decided only by your hematology team.
07Key terms
- Antiemetic
- A medicine against nausea and vomiting.
- Acute nausea
- Nausea in the first 24 hours after a medicine.
- Delayed nausea
- Nausea that starts a day or more after a medicine.
- Anticipatory nausea
- Nausea before treatment, caused by past experience.
- Emetic risk
- How likely a treatment is to cause nausea.
- Mucositis
- Inflammation and sores of the lining of the mouth and gut.
- Dehydration
- Losing too much fluid from the body.
- Nutritional drink
- A ready-made drink with a lot of energy and protein in a small volume.
08Key points
- Take anti-sickness medicines as prescribed, without waiting for nausea.
- If a medicine is not helping, tell your team.
- Eat little and often.
- Sip fluids between meals.
- When appetite is poor, eat by the clock.
- Mouth care helps prevent sores.
- If fluids will not stay down, call straight away.
- Hard days pass; ask for help.
09Frequently asked questions
If I have no nausea, should I still take the medicine?
If it has been prescribed for prevention at set times, yes; it is there to stop nausea from starting. If you want to change anything, talk to your team first.
Can I drink ginger tea?
Ginger tea in ordinary amounts or ginger in food is pleasant for many people. Ginger capsules and concentrated supplements, however, can interact with medicines, so discuss them with your team first.
Should I eat on treatment day?
A light meal is usually better than an empty stomach. Avoid heavy, greasy food. If your team has given special instructions, follow them.
I cannot eat anything all day. Is that dangerous?
One day of eating little is usually not dangerous, but drinking matters. If fluids will not stay down, or you have eaten almost nothing for a day or two, call your team.
My family keeps pushing me to eat. What can I do?
Your loved ones do it out of care. Explain that large portions can make nausea worse, while small, frequent meals help more. Reading this topic together may help.
When will my appetite come back?
Appetite usually recovers gradually between treatment cycles and after treatment ends. Discuss long-lasting poor appetite and weight loss with your team and a dietitian.
10Questions for your doctor
Take these questions to your appointment. The ones you save are collected on the “My questions” page and stay on this device only.
Which anti-nausea medicine should I take, and how?
If I have no appetite, which foods may be easier to manage?
When is vomiting an urgent situation?
What can be done if mouth sores make eating hard?
12Sources
- National Cancer Institute (NCI). Nausea and Vomiting Related to Cancer Treatment
- National Cancer Institute (NCI). Nausea and Vomiting Related to Cancer Treatment (PDQ®) – Patient Version
- National Cancer Institute (NCI). Appetite Loss and Cancer Treatment
- National Cancer Institute (NCI). Mouth and Throat Problems during Cancer Treatment
- National Cancer Institute (NCI). Eating Hints: Before, during, and after Cancer Treatment
- American Cancer Society. Nausea and Vomiting
- American Cancer Society. Poor Appetite
- American Cancer Society. Taste and Smell Changes
- Cancer.Net (ASCO). Nausea and Vomiting
- National Center for Complementary and Integrative Health (NCCIH). Ginger
- Journal of Clinical Oncology, 2020. Antiemetics: ASCO Guideline Update
- Supportive Care in Cancer, 2023. 2023 updated MASCC/ESMO consensus recommendations: prevention of nausea and vomiting following high-emetic-risk antineoplastic agents
- Cancer, 2020. MASCC/ISOO clinical practice guidelines for the management of mucositis secondary to cancer therapy
- Journal of Clinical Oncology, 2020. Management of Cancer Cachexia: ASCO Guideline