The connection between sleep and immune health

Sleep and immune health are closely linked. During sleep your body adjusts the immune cells and chemical signals that help fight infection, and studies connect regularly sleeping under six hours with a higher chance of catching colds and a weaker response to some vaccines. Most adults need seven to nine hours.

What does sleep do for the immune system?

Your immune system is a network of cells and chemical messengers, called cytokines, that spot and respond to infections. Sleep seems to keep that network running properly. In studies where healthy people were kept awake for a night, researchers saw clear changes in which immune cells were circulating in the blood and which chemical messengers the body released. Other work has found that sleep helps regulate T cells, the cells that identify and attack infected cells.

The link runs in both directions. Immune responses can affect how well you sleep, too. Your body clock also shapes when some immune activity peaks, which is one reason shift workers are a group researchers watch closely.

Does too little sleep make you more likely to get sick?

One of the clearest studies on this was published in the journal Sleep in 2015. Researchers had 164 healthy adults wear wrist sensors for a week to measure how long they slept. They then dripped a cold virus into the participants’ noses and kept them under observation to see who got sick.

People who had slept under six hours a night were about four times as likely to develop a cold as those who had slept more than seven. The risk was slightly higher still for those averaging five hours or less. Around four in ten of the short sleepers got sick, against fewer than two in ten of the longer sleepers. The lead author reported that sleep predicted illness better than age, stress levels, income or smoking.

There are limits. The study shows an association, not proof that short sleep causes colds, and it looked at healthy adults and one virus. It’s still among the more convincing pieces of evidence, because it measured people’s normal sleep instead of forcing them to stay awake.

Does sleep affect how well vaccines work?

It may. A 2023 analysis in Current Biology pooled seven studies on influenza and hepatitis A and B vaccines. When sleep was measured objectively, people who slept under six hours around the time of vaccination made fewer antibodies than people who slept seven to nine hours. The effect was clear in men. In women the results were more variable, and the researchers said more data were needed. Studies relying on self-reported sleep didn’t reach statistical significance.

The researchers also said the best window for getting good sleep around a vaccination hasn’t been pinned down yet. So don’t read this as a reason to postpone a shot because you slept badly the night before. Getting vaccinated matters more.

How much sleep do you actually need?

For adults, the usual recommendation is seven to nine hours a night. The studies above flagged regularly getting under six. That doesn’t mean seven hours is a magic line for immunity, since nobody has measured that precisely.

Duration isn’t the whole picture either. Broken sleep can leave you tired even when the clock says eight hours, though most of the research here measured how long people slept, not how well.

What helps you sleep better?

A few habits are worth trying:

1. Keep a regular bedtime and wake time, including weekends.
2. Make the room dark, quiet and on the cooler side.
3. Put screens away for the last half hour before bed.
4. Cut off caffeine by mid-afternoon.
5. Keep the bed for sleeping, not for working or scrolling.

Your bed matters too, though only in a limited way. A mattress won’t do anything for your immune system directly. What it can do is remove one common reason for broken sleep, like waking with a sore shoulder or hip. The Neobest Orthopaedic Memory Foam Mattress pairs a firm base with a memory foam comfort layer, which suits people who want support with some cushioning on top.

Keeping the bed itself fresh helps with comfort as well. Wash your sheets regularly, and a mattress protector makes that easier by keeping spills and sweat off the mattress surface.

When should you talk to a doctor?

If you regularly can’t fall asleep, wake up exhausted after a full night, snore loudly or wake up gasping, it’s worth seeing a doctor. The same goes for catching infections unusually often. This post isn’t medical advice, and better sleep isn’t a replacement for vaccination or treatment.

FAQs

Can sleeping more cure a cold?

No. Sleep supports your body’s defenses, but it isn’t a treatment. Resting when you’re ill is sensible, and anything severe or lasting should be checked by a doctor.

How many hours of sleep do you need for a healthy immune system?

Adults are generally advised to get seven to nine hours. No one has found an exact figure for immunity, but the studies above flagged regularly sleeping under six hours.

Can you catch up on lost sleep over the weekend?

A longer night after a short week can help you feel better. The research mostly looked at regular sleep patterns, though, so a steady schedule is the safer bet.

Does sleep matter around the time of a vaccination?

Researchers think it may, and they suggest getting enough sleep in the days around the shot. The best timing isn’t established, and you shouldn’t delay vaccination because of it.

Does a better mattress improve immunity?

There’s no direct evidence for that. A comfortable, supportive bed may help you sleep more steadily, and it’s the sleep that the research connects to immune health.

If you’re thinking about your sleep setup, you can explore Neobest mattress collections.