Low White Blood Cells in Lymphoma: What It Means

Low white blood cell counts are common in people with lymphoma, especially during treatment, and they mainly matter because they increase the risk of infection. Chemotherapy and some targeted or radiation therapies can temporarily lower white blood cells (particularly neutrophils), which are the body’s front‑line defenders against germs. ^[1] This drop, called neutropenia, is expected after many chemotherapy regimens and is the primary reason clinicians monitor blood counts closely and give specific prevention advice. ^[1]

Why counts get low

• Lymphoma itself can affect the bone marrow, where blood cells are made, which may contribute to low counts. ^[2]
• More commonly, chemotherapy and radiation kill fast‑growing cancer cells but also affect healthy fast‑growing cells, including white blood cells. ^[1]
• Some immunotherapy or antibody-based treatments can also suppress parts of the immune system, adding to infection risk. ^[3]

What “neutropenia” means

Neutropenia is a low level of neutrophils, a type of white blood cell that fights bacteria and fungi. When neutrophils are low, your body has a harder time stopping infections early, and minor infections can turn serious more quickly. ^[1] The lowest point in counts (the “nadir”) typically occurs about 7–12 days after chemotherapy, though the exact timing depends on the drugs you receive. ^[4]

When to be concerned

You should be especially alert to symptoms of infection while your counts are low, because infections can escalate quickly and become life‑threatening if not treated promptly. ^[5] Concerning signs include fever of 38.0°C (100.4°F) or higher, chills, worsening cough, shortness of breath, sore throat, burning with urination, severe mouth sores, redness or drainage at catheter/IV sites, or any rapidly worsening symptoms. ^[6] If you develop a fever at any time during neutropenia, it is considered an emergency that needs same‑day medical assessment. ^[5]

Practical steps to reduce risk

There isn’t much you can do to stop neutropenia itself because it’s usually caused by treatment but you can lower infection risk with daily habits and good timing. ^[4]

• Hand hygiene: Wash hands often or use alcohol-based sanitizer, especially before eating and after restroom use. ^[7]
• Avoid sick contacts and crowded indoor spaces when your counts are lowest. ^[8]
• Food safety: Choose well‑cooked foods, avoid raw eggs/seafood, wash produce well, and follow safe food handling. ^[9]
• Skin and mouth care: Use an electric shaver, be gentle with dental care, and protect skin from cuts or burns that can let germs in. ^[8]
• Pet precautions: Avoid cleaning litter boxes or handling animal waste; have someone else help if possible. ^[9]
• Know your nadir: Ask your team when your counts will be lowest after each cycle so you can be extra careful during that window. ^[4]
• Vaccines: Your team may recommend inactivated vaccines at appropriate times; live vaccines are usually avoided during significant immunosuppression. ^[10]

Treatments that help counts recover

Your oncology team may prescribe granulocyte colony‑stimulating factor (G‑CSF; filgrastim or pegfilgrastim) after chemotherapy to help your white blood cells recover faster and reduce the risk of infection. ^[11] These are given as injections (either daily for several days or a single long‑acting dose) based on your regimen and risk. ^[12]

How your team monitors you

Because you can’t reliably feel when counts are low, regular blood tests are used to track white blood cells and neutrophils during treatment. ^[13] Your clinician will interpret the numbers for your situation, since “normal ranges” vary by lab and person, and advise about precautions and when to seek care. ^[14]

Quick reference: Warning signs and actions

Situation	What to look for	What to do
Possible infection during low counts	Fever ≥38.0°C (100.4°F), chills, cough, shortness of breath, sore throat, burning with urination, severe mouth sores, redness/swelling at IV sites, new rash	Call your oncology team immediately or go to urgent care/ER the same day, especially with fever
During nadir (about days 7–12 after chemo; varies)	General weakness, signs of illness, any new symptoms	Use strict hygiene and avoidance steps; monitor temperature regularly; contact your team early with concerns
Repeated or severe neutropenia	Prior infections, hospitalization for fever	Ask about G‑CSF support and individualized prevention plans

Fever during neutropenia is an emergency because infections can progress fast; prompt antibiotics may be lifesaving. ^[5] Keeping a thermometer at home and knowing your team’s after‑hours contact process can make a real difference. ^[6]

Bottom line

• Low white blood cells are common in lymphoma, especially with chemotherapy, and mainly increase infection risk. ^[1]
• The risk is usually temporary and manageable with precautions, timely reporting of symptoms, and, when appropriate, supportive medicines like G‑CSF. ^{[4] [11]}
• If you develop a fever of 38.0°C (100.4°F) or higher or feel acutely unwell while counts are low, seek urgent care the same day. ^{[6] [5]}

Staying informed about your nadir days, practicing daily infection‑prevention steps, and communicating quickly with your care team are the safest ways to navigate low counts during lymphoma treatment. ^{[4] [7]}