The short answer
NCI's chemotherapy booklet places dizziness alongside anemia, meaning low red blood cell counts. Standing up slowly helps in the moment. Feeling like you might faint is on NCI's list of reasons to call your doctor or nurse. During chemotherapy, call your care team right away.
NCI's chemotherapy guide discusses dizziness in the context of anemia, a low red blood cell count.
Standing up slowly is NCI's practical advice, since rising too fast can make you dizzy.
When getting up from lying down, NCI suggests sitting for a minute before standing.
NCI lists feeling dizzy or like you might faint as a reason to call your doctor or nurse. If you are on chemotherapy, call right away.
On this page
Choose how you want to read this
The whole article, with every detail and caution.
This page is for people who feel dizzy or lightheaded during chemotherapy. It covers when to call, how anemia can cause it, and how to lower the risk of falls.
When to get help sooner
- Call 911 if you faint and do not become alert within a couple of minutes. Call 911 if dizziness or fainting comes with chest pain or pressure, trouble breathing, a pounding or irregular heartbeat, trouble speaking, vision problems, or weakness in an arm or leg. Call 911 if fainting caused a fall with an injury or bleeding, or came with a seizure, a tongue injury, or loss of bladder or bowel control. MedlinePlus also says to call 911 after fainting if the person is over 50, is pregnant, or has diabetes. Call 911 too if you cannot stay upright or safely get to a phone (MedlinePlus, MedlinePlus).
- Call your care team right away, day or night, if you feel dizzy or like you are going to faint, if you feel short of breath, if it feels like your heart is pounding or beating very fast, or if your level of fatigue changes so that you cannot do your usual activities. NCI lists these four together as reasons to call your doctor or nurse. During chemotherapy, do not wait for your next scheduled visit.
- Call your care team right away, day or night, for a temperature of 100.4°F (38°C) or higher (CDC), or for chills or any other sign of infection (CDC). NCI says infections during cancer treatment can be life threatening and need urgent medical attention. Do this even if dizziness is the only other thing you notice. Dizziness with a fever can come from an infection, so do not wait.
Anemia is treatable, and your team needs to know while the symptom is happening.
Where the dizziness is coming from
Where NCI places dizziness tells you something. It appears in the anemia section of NCI's chemotherapy guide.
Anemia means your red blood cell count is low. Red blood cells carry oxygen. NCI says some types of chemotherapy cause anemia because they make it harder for bone marrow to produce new red blood cells.
NCI says anemia can make you feel short of breath, weak, dizzy, faint, or very tired. Your heart works harder when your body does not get enough oxygen. That can make it feel like your heart is pounding or beating very fast.
This is why dizziness appears alongside the other symptoms on that call list. Breathlessness, a racing heart and heavy fatigue can all come from the same shortage.
Anemia is not the only possible cause. MedlinePlus lists a sudden drop in blood pressure, dehydration, standing up too fast and some medicines as other causes of lightheadedness. Your team can sort out which one fits you.
If you are dizzy and also worn out and short of breath, call your care team right away. NCI links these symptoms to anemia.
The practical advice, which is smaller than you would expect
NCI's in-the-moment guidance is plain.
Stand up slowly. You may feel dizzy if you stand up too fast. When you get up from lying down, sit for a minute before you stand.
Build it into your routine on treatment weeks. Sit on the edge of the bed for a minute before your feet take your weight. These are habits, not emergencies.
Falls are a real risk
Think about where you are most likely to go down: the bathroom at night, the stairs, getting out of the shower, standing up from the sofa when the phone rings. Those are the moments to slow down deliberately.
NCI's chemotherapy guide gives these fall-prevention tips in its section on nerve changes (neuropathy), and they apply here too. Walk slowly. Hold onto handrails when using the stairs. Put no-slip mats in the bath. Tell your team about any near-falls.
What your team can actually check
The useful thing about anemia is that it is measurable. NCI says your doctor or nurse will check your blood cell count throughout your chemotherapy. Your team can compare your red cell count now with your earlier results.
NCI says you may need a blood transfusion if your red blood cell count falls too low. Your doctor may also prescribe a medicine to boost red blood cell growth, or suggest iron or other vitamins.
That is why the call is worth making. You are not asking them to guess from a description. You are giving them a symptom that they can match against a number they already track.
Say it out loud at the next appointment
Dizziness is one of those symptoms people skip over because it feels vague and because there is always something bigger to discuss in a fifteen-minute appointment.
Bring it up anyway. Mention when it happens, what you are doing when it hits, how long it lasts, and whether you have come close to falling. That last detail in particular tends to get attention, and it should.
Sources
Common questions
Is dizziness after chemo normal?
NCI addresses it directly in its anemia section, and anemia is one cause of dizziness. That does not make it something to ignore. NCI lists feeling dizzy or faint as a reason to call your doctor or nurse. During chemotherapy, call right away instead of waiting for your next visit.
What can I do in the moment?
NCI's advice is to stand up slowly, and when you are getting up from lying down, to sit for a minute before you stand. NCI says you may feel dizzy if you stand up too fast.
How would my team know if it is anemia?
Red blood cell counts are part of routine blood work during chemotherapy. Your team can compare your counts against earlier ones and see whether they have dropped.
What else on that list should I watch for?
NCI groups dizziness with shortness of breath, a heart that feels like it is pounding or beating very fast, and a change in your fatigue level that stops you doing your usual activities.
Questions to ask your doctor
Being prepared helps you get the most out of your appointments. Save or print these questions.
Tap a question to save it to your list (kept on this device).
Your next step
Turn this topic into questions for your next appointment.
Talk with a trained specialist or navigator
Cancer Explained provides educational guidance, but does not replace trained specialists, social workers, or your medical team.
Talk to a trained cancer information specialist
Free, confidential assistance from NCI Cancer Information Service via phone, chat, or email.
Contact your oncology team
Locate after-hours contact numbers, portal messages, or urgent triage phone lines.
Find a patient navigator
Get one-on-one help with appointments, logistics, translation, and care coordination.
Find a genetic counselor
Discuss inherited mutation risk, family history, and genetic testing options.
Find an oncology social worker
Access emotional counseling, family support groups, and mental health resources.
Find a financial navigator
Locate copay assistance foundations, grant programs, and lodging/travel support.
Find a clinical-trial specialist
Search matching studies and speak with NCI trial information specialists.
Get urgent help
Fever of 100.4°F (38°C) or higher during chemo, severe pain, or trouble breathing: call your cancer care team right away, day or night. Call 911 for an emergency.
Know someone who needs this?
Plenty of people are looking for something like this and do not know where to start. If this would help a friend or someone you love, send it on — we have written an opening line so you do not have to stare at an empty message. You can change every word of it.
Your message is written and sent in your own email or messaging app — we never see who you send it to, and nothing is added to any list.
Plain-language explanation of the published sources cited on this page. AI-assisted, source-checked, not clinician-reviewed.
Sources last checked: 2026-08-11 what this meansLast updated: 2026-10-01Next planned review: 2027-08-11
Review details and limits
Cancer Explained does not originate medical claims. Every page restates guidance already published by the National Cancer Institute, the CDC, the USPSTF and the FDA, in plain language, with the source cited so you can check the original yourself. AI does the translating and organizing; automated checks test claims, citations, clarity and safety before anything publishes, and this is translation and navigation, not clinical judgment. Nothing here is personal medical advice, and no page can account for your particular situation.
Editorial status — Source checked. This page was written with AI assistance and then compared with the sources listed on it, looking for statements those sources do not back up. That check is not a sentence-by-sentence record and can miss errors. It is not a medical review, and it does not confirm the page is complete or right for your situation.
High-risk topic — talk to your care team. This topic can involve urgent, individual medical decisions. This page is general education only: it cannot tell you whether your situation is an emergency or what you personally should do. Follow your oncology team's instructions and contact them for individual guidance.
Human medical review: not completed. Pages here are not signed off by a clinician before they publish. That is not an oversight we are quietly working around: we restate published guidance and cite it, so the authority belongs to the source rather than to us, and every page names where its claims come from — you can verify us instead of trusting us. Where a volunteer clinician has reviewed a page, their name and credentials appear on it; where no name appears, no clinician has checked it. We are glad to have reviewers and are recruiting them, and we do not hold pages back waiting for one. Use this site to understand your situation and to ask better questions of the people treating you.
Words to know
Tap any term to see what it means.
How this page was created
Cancer Explained does not originate medical claims. Every page restates guidance already published by the National Cancer Institute, the CDC, the USPSTF and the FDA, in plain language, with the source cited so you can check the original yourself. AI does the translating and organizing; automated checks test claims, citations, clarity and safety before anything publishes, and this is translation and navigation, not clinical judgment. Nothing here is personal medical advice, and no page can account for your particular situation.
Editorial status: Source checked — This page was written with AI assistance and then compared with the sources listed on it, looking for statements those sources do not back up. That check is not a sentence-by-sentence record and can miss errors. It is not a medical review, and it does not confirm the page is complete or right for your situation.
Human medical review: not completed. Pages here are not signed off by a clinician before they publish. That is not an oversight we are quietly working around: we restate published guidance and cite it, so the authority belongs to the source rather than to us, and every page names where its claims come from — you can verify us instead of trusting us. Where a volunteer clinician has reviewed a page, their name and credentials appear on it; where no name appears, no clinician has checked it. We are glad to have reviewers and are recruiting them, and we do not hold pages back waiting for one. Use this site to understand your situation and to ask better questions of the people treating you.
Read more about our editorial process, our use of AI, and our corrections policy.
Spotted a problem? Report an error — a factual mistake, broken or outdated source, confusing wording, or anything that seems unsafe. Please do not include names, medical record numbers, dates of birth, addresses, or other identifying medical information in your report.
After using this page, do you understand what to do next?
Anonymous — we only record the answer, never who gave it.