Chemo weeks 2 to 3 side effects: the nadir, fatigue, and changes that build

This post is part of our chemo series. For the full cycle at a glance, see chemo side effects week by week.

The nadir period

The nadir is the low point in blood counts after a dose of chemo. For many regimens it falls somewhere in the second week, but it can be earlier or later. During this time white blood cells, which fight infection, may be low.

Many people feel better during the nadir than they did in week 1, which is why it is easy to overlook. Your team may check blood counts during this window.

Many teams ask you to call right away if you have a temperature of 100.4°F (38°C) or higher, or the number your team gave you, or shaking chills. Follow the exact instructions from your care team. For emergencies, call 911.

Fatigue

Chemo fatigue can feel different from ordinary tiredness. It may come and go, or build over the weeks. Many people find it helps to plan important tasks for the times of day when they tend to feel best, and to accept help with meals and errands.

Tell your care team if fatigue is getting in the way of eating, drinking, or daily life. Sometimes there is a cause they can check, such as low red blood cells.

Taste and mouth changes

Food may taste metallic, bland, or too salty. Some people get a dry mouth or mouth sores. Things people often find useful include:

• Asking the team about a gentle mouth rinse
• Using a soft toothbrush
• Trying cold or room temperature foods
• Telling the team early if sores make it hard to eat or drink

Hair loss timing

Not every chemo causes hair loss. When it does happen, it often starts a few weeks after the first treatment, commonly in this weeks 2 to 3 window. It may be gradual thinning or happen more quickly. Your care team can tell you whether hair loss is expected with your treatment.

Effects that build across cycles

Some effects can grow over several cycles. Common examples include tiredness, numbness or tingling in the hands or feet, and changes in skin or nails. These are worth tracking, because your team may adjust care if they get worse.

Tell your team about any new numbness, tingling, or trouble with buttons or walking.

Questions to raise in weeks 2 to 3

• When is my nadir likely to be with this regimen?
• Will you check my blood counts, and when?
• What temperature should make me call, and what number do I use after hours?
• Is hair loss expected with my treatment?
• Which effects should I tell you about before my next cycle?

Keep reading the series

• Chemo side effects week by week
• Chemo week 1: infusion day, the steroid window, and the first crash
• The final weeks of chemo and recovery