‘How soon after chemotherapy do side effects start?’

Q1. How soon after a chemotherapy session do patients typically begin to experience side effects? Does the timing differ from person to person?

Chemotherapy side effects, as per Dr Upadhyay, can begin as early as a few hours to a couple of days after treatment, “depending on the type and dosage of the drugs used.” He explains that each person’s body reacts differently based on factors like age, overall health, and metabolism. “Some patients may notice nausea or fatigue within the first 24 hours, while others might not experience any discomfort until two to three days later.”

Chemotherapy is widely used for the treatment of cancer

Q2. Which side effects appear first after chemotherapy — for example, nausea, fatigue, or hair loss — and how long do they usually last?

“The earliest side effects often include nausea, vomiting, and fatigue, as chemotherapy temporarily affects healthy cells in the stomach lining, bone marrow, and energy-producing systems,” he notes. Hair loss, the most infamous symptom, usually appears after two to three weeks, according to the oncologist. This is because it takes time for the drugs to affect hair follicles. “Nausea and fatigue may last for a few days after each cycle, but with proper medication and rest, they generally improve before the next session.”

Q3. Are there certain warning signs in the first few days after chemo that patients or caregivers should watch out for and report immediately?

Dr Upadhyay cautions that patients should watch for warning signs such as high fever, severe vomiting, difficulty breathing, persistent diarrhoea, or any signs of infection like redness or swelling at the injection site. “A sudden drop in white blood cell count can make patients more vulnerable to infections, so any unusual weakness or fever should be reported to the doctor immediately,” he notes.

Chemotherapy medicines can be administered through an IV drip, injections, pills, or, in some cases, creams (photo: pexels)

Q4. What steps can patients take to manage or reduce early side effects?

Patients can manage early side effects by staying hydrated, eating small and balanced meals, and getting plenty of rest, as advised by Dr Upadhyay, who further adds that anti-nausea medications prescribed by the oncologist should be taken on time. “Gentle physical activity, like short walks, can also help improve energy levels and mood.”

Q5. Do side effects tend to get milder or worse with subsequent chemotherapy sessions, and how does the body adapt over time?

The side effects can vary with each cycle. “For some, the body gradually adapts, and symptoms become more predictable and manageable. However, for others, cumulative fatigue or weakness may occur,” he points out. Regular monitoring, timely medications, and open communication with the oncology team are key to minimising discomfort and ensuring treatment continues safely, the oncologist concludes.

DISCLAIMER: This article is based on information from the public domain and/or the experts we spoke to. Always consult your health practitioner before starting any routine.