Immune Health

About immune health

What it is, why it happens and what helps. Contents:

• What is the immune system?
• Can you boost your immune system?
• Sleep
• Exercise
• Food and nutrition
• Gut health
• Stress and immunity
• Meditation and mindfulness
• Relaxation
• Friends, hugs and connection
• Cold water and cold showers
• The Wim Hof Method
• Everyday habits
• Immunity as we age
• A simple 30-day plan
• How self-help methods fit in
• FAQs

What is the immune system?

Your immune system is the body’s defence network. It includes white blood cells, antibodies, the lymph system, the skin and the lining of your gut and airways, all working together to spot and deal with germs and repair damage. It has two main parts. The innate immune system acts fast and responds to any invader. The adaptive immune system learns to recognise specific germs and remembers them, which is how vaccines and past infections protect you. Kurzgesagt’s animated video in Videos gives a lovely overview. You can explore related topics in our Health hub, including sleep, gut health and healthy eating.

Can you boost your immune system?

A healthy immune system is balanced, not simply “boosted”. It needs to respond strongly to germs, then calm down again. Rather than looking for a single quick fix, the best approach is a set of everyday habits that support your body: good sleep, regular movement, nourishing food, stress care and connection with others. These are the habits with the most research behind them, and they also help your energy, mood and long-term health.

Sleep

Sleep is when your body does much of its repair work, and it plays an important role in immunity. In a study where 164 healthy adults were given cold virus drops, those who slept less than six hours a night were about four times more likely to develop a cold than those who slept more than seven hours. [1] An earlier study of 153 adults found that people who slept less than seven hours were nearly three times more likely to catch a cold than those who slept eight hours or more. [5] Aim for seven to nine hours, with regular sleep and wake times. Matt Walker’s TED talk, Sleep is your superpower, is in Videos, and our sleep guide has practical tips.

Exercise

Regular moderate exercise is one of the best things you can do for your immune system. A review of exercise immunology research found that regular activity supports immune surveillance, the way immune cells patrol the body, and is linked to fewer respiratory infections and lower inflammation. [2] Brisk walking, cycling, swimming, dancing and gardening all count. Aim for around 150 minutes of moderate activity a week, the amount recommended by health services in the UK, the US and many other countries. The NHS exercise pages in Free resources have ideas for every fitness level.

Food and nutrition

Your immune system needs a range of nutrients to work well, including protein, vitamins A, C, D and E, zinc, selenium and iron. A varied diet with plenty of vegetables, fruit, whole grains, beans, nuts, seeds, fish and some dairy or other calcium sources provides most of what you need. In many countries, including the UK, health services advise considering a vitamin D supplement during autumn and winter when there is less sunlight. If you’re thinking about other supplements, talk to a pharmacist or doctor. Our guides to healthy eating and supplements have more information.

Gut health

A large part of your immune system lives in and around your gut, where it interacts with trillions of microbes. Eating a wide variety of plant foods, plus fibre-rich and fermented foods such as yoghurt, kefir, kimchi and sauerkraut, helps support a diverse gut community. Our gut health guide explains more.

Stress and immunity

Short bursts of stress are a normal part of life and the body handles them well. Ongoing stress, though, can affect how your immune system works. In a classic study of 394 people given cold virus drops, the chance of catching a cold rose steadily with stress levels, from about 27% in the least stressed group to about 47% in the most stressed. [3] This is encouraging, because stress is something you can learn to manage. TED-Ed’s video on how stress affects your body is in Videos, and our stress management guide has many everyday tools.

Meditation and mindfulness

Meditation and mindfulness help many people feel calmer and cope better with stress. A review of randomised trials found possible effects of mindfulness meditation on markers of inflammation, immune cell activity and biological ageing, while noting that more research is needed. [6] Start with five to ten minutes a day, sitting quietly and focusing on your breath. Our guides to meditation and mindfulness explain how.

Relaxation

Relaxation practices help switch on the body’s calming system. Progressive muscle relaxation, where you gently tense and release each muscle group, is a simple place to start. Other options include body scans, guided imagery, gentle yoga and slow breathing. A few minutes of relaxation before bed can also help you sleep. Our relaxation guide walks you through it.

Friends, hugs and connection

Warm relationships are good for your health. In a study of 404 adults, people who felt more supported, and those who received more hugs, were better protected against the extra infection risk that comes with stress. [4] Spending time with friends and family, joining a group or club, volunteering and simply staying in touch all help. Our guide to loneliness and making friends has ideas.

Cold water and cold showers

Cold water has become a popular wellbeing practice. In a Dutch study with 3,018 people, those asked to end their daily hot shower with 30 to 90 seconds of cold water took 29% fewer sick days from work than the control group, although the number of days they felt ill was similar. [7] Many people say a cold finish to their shower leaves them feeling energised. If you’d like to try it, start with a few seconds and build up gradually. If you have a heart condition or high blood pressure, check with your doctor first.

The Wim Hof Method

The Wim Hof Method combines a special breathing technique, gradual cold exposure and focus. In a study published in PNAS, 24 healthy volunteers were randomly assigned to training or no training. The trained group then received a substance that triggers flu-like symptoms in a controlled hospital setting. Compared with the untrained group, they produced more of an anti-inflammatory messenger called IL-10, less of several inflammatory messengers and reported fewer flu-like symptoms. [8] This was a small study, and researchers continue to explore what it means for everyday health. Wim Hof’s guided session for beginners is in Videos, and you can read more on Wim Hof’s page.

Everyday habits

• Wash your hands with soap and water, especially before eating.
• Keep up to date with the vaccines recommended for you.
• Get outside in daylight and fresh air.
• Stay hydrated.
• Drink less alcohol and avoid smoking. Our guides to cutting down on alcohol and quitting smoking can help.
• Rest when you’re unwell, so your body can recover.

Immunity as we age

The immune system naturally changes with age, which is one reason vaccines are especially important for older adults. The same healthy habits, including staying active, eating well, sleeping well and staying socially connected, help support immunity at every age. Our healthy ageing guide has more ideas.

A simple 30-day plan

Week 1: Sleep. Set a regular bedtime and aim for at least seven hours.

Week 2: Move. Add a brisk 20 to 30 minute walk on most days.

Week 3: Calm. Practise ten minutes of meditation, relaxation or slow breathing each day.

Week 4: Nourish and connect. Add an extra portion of vegetables daily, and arrange time with friends or family.

How self-help methods fit in

Meditation, mindfulness and relaxation help calm the stress response and support restful sleep. The Wim Hof Method combines breathing, cold and focus, and gentle yoga and qigong blend movement and calm. These work best alongside good sleep, regular activity, healthy food and the vaccines recommended for you. You can see every method we cover in the full list above.

Frequently asked questions

Can you boost your immune system?

A healthy immune system is balanced rather than boosted. Good sleep, regular exercise, healthy food, stress care and social connection all support it.

Does sleep affect immunity?

Yes. People who slept less than six hours were about four times more likely to develop a cold than those who slept more than seven. [1]

Does stress weaken the immune system?

Ongoing stress can affect immunity. In one study, the chance of catching a cold rose with stress levels. [3]

Does exercise help the immune system?

Regular moderate exercise is linked to better immune surveillance and fewer respiratory infections. [2]

Do cold showers help?

In one large study, people who finished their shower with cold water took fewer sick days, although days of feeling ill were similar. [7]

What does the Wim Hof Method do?

In a small study, trained volunteers had a more anti-inflammatory response and fewer flu-like symptoms in a controlled test. [8]

Which foods support the immune system?

A varied diet with vegetables, fruit, whole grains, beans, nuts, seeds and fermented foods provides the nutrients your immune system needs.

The best videos on immune health

Hand-picked and checked one by one: Kurzgesagt, TED, TED-Ed, Go Condition and Wim Hof’s official channel.

How your immune system works

Sleep, stress and immunity

Exercise and breathing

Books on immune health

Free resources

Experts to follow

Get help

If you get frequent or severe infections, please see your doctor, and only ever practise Wim Hof breathing sitting or lying down on dry land, never in water or while driving.

Find a therapist or counsellor

• US and Canada: Psychology Today (US) and (Canada) directories.
• UK: BACP therapist directory.
• Australia: APS Find a Psychologist, and Relationships Australia for couple and family services.
• Elsewhere, including Europe and India: ask your doctor or local health service for a referral, and check that anyone you see is registered or accredited where you live.

This hub is for information, not a substitute for medical or psychological care.

Sources

1. Prather et al. (2015), Behaviorally assessed sleep and susceptibility to the common cold, Sleep 38(9):1353-1359
2. Nieman and Wentz (2019), The compelling link between physical activity and the body’s defense system, Journal of Sport and Health Science 8(3):201-217
3. Cohen, Tyrrell and Smith (1991), Psychological stress and susceptibility to the common cold, New England Journal of Medicine 325(9):606-612
4. Cohen et al. (2015), Does hugging provide stress-buffering social support? Psychological Science 26(2):135-147
5. Cohen et al. (2009), Sleep habits and susceptibility to the common cold, Archives of Internal Medicine 169(1):62-67
6. Black and Slavich (2016), Mindfulness meditation and the immune system: a systematic review of randomized controlled trials, Annals of the New York Academy of Sciences 1373(1):13-24
7. Buijze et al. (2016), The effect of cold showering on health and work: a randomized controlled trial, PLOS ONE 11(9):e0161749
8. Kox et al. (2014), Voluntary activation of the sympathetic nervous system and attenuation of the innate immune response in humans, PNAS 111(20):7379-7384

Written by Saj Ali. Last updated 3 November 2026. Spotted an error? Tell us and we will fix it.