Can too little sleep make you more susceptible to infections?
Too little sleep demonstrably makes your immune system more vulnerable, including to infections and vaccinations. Make sure you get sufficient sleep, even though the exact numbers and thresholds are not yet precisely known.
Too little sleep increases your chances of becoming ill from infections. This applies both to catching a disease more readily and to fighting it less effectively. The immune system needs sleep for two types of defence: the fast, general response and the more specific, longer-lasting response that also protects you after vaccinations. Both are disrupted by sleep deprivation.
A concrete example: people who sleep too little before or after a vaccination build up less protection. The vaccine then works less effectively. This has been studied in both epidemiological studies and laboratory research, and the association is confirmed in multiple studies.
Sleep deprivation also raises the level of inflammation-promoting substances in your blood. With short-term sleep loss this is temporary, but with chronic sleep deprivation a persistent, low-grade inflammation develops in the body. This smouldering inflammation is thought to contribute to conditions such as diabetes, cardiovascular disease and possibly neurodegenerative disorders, although the precise causal chain has not yet been fully mapped out.
More or better sleep appears to have the opposite effect: the immune system recovers and functions better. But the evidence for this is still limited; there are methodological challenges and open research questions remain. Concrete recommendations about how much extra sleep you need in order to be protected cannot yet be distilled from the studies.
Exact risk figures, such as 'x percent greater chance of catching a cold', are not provided in the available studies. But the direction is clear and is broadly supported: structurally too little sleep makes your immune system more vulnerable.
Based on multiple epidemiological and laboratory studies (PMID: 30920354, 34795404, 39154978, 27510422, 25315456, 37322182, 34074604). No exact risk figures available in the abstracts. Strength of evidence for infection risk and inflammation is moderate; for recovery through more sleep the evidence is more limited.
Does too little sleep weaken your immune system?
Yes, too little sleep demonstrably weakens your immune system and increases the risk of infections and chronic inflammatory conditions. Seven to nine hours of sleep is the most commonly cited guideline, and vaccinations also work better when you are well rested.
What does sleep deprivation do to your immune system?
Sleep deprivation demonstrably weakens your immune system: sleeping fewer than six hours significantly increases your infection risk and impairs your immune cells. Make sure to structurally get seven hours or more, because a single recovery night is not enough to repair the damage.
What does chronic sleep deprivation do to your inflammation in the long run?
Chronic sleep deprivation demonstrably raises inflammatory markers in your blood and is linked to diseases such as cardiovascular disease and dementia; getting enough sleep is therefore one of the most concrete things you can do yourself to limit chronic inflammation.
Why do older adults become seriously ill from an infection more quickly?
Ageing weakens the immune system in several ways simultaneously, making infections more dangerous. Keep vaccinations up to date and discuss nutritional deficiencies with your doctor, as these additionally increase vulnerability.
Why do you get sick more often when you are on a diet?
A low-calorie diet can weaken your immune system through deficiencies in minerals such as magnesium, disrupted gut bacteria and suppressed immune responses. When dieting, pay attention to adequate micronutrient intake to limit this risk.
Can too much sugar weaken your immune system?
Chronically high blood sugar levels, as seen in diabetes or severe obesity, demonstrably weaken immune defences. For healthy people without these conditions, the effect of ordinary sugar consumption on the immune system has not yet been demonstrated.