The most effective ways to avoid getting sick come down to a handful of daily habits: washing your hands properly, sleeping enough, staying physically active, keeping up with vaccines, and improving the air quality in your spaces. None of these are surprising on their own, but the details of how and why they work can make the difference between doing them halfheartedly and doing them well enough to matter.
Wash Your Hands the Right Way
Soap doesn’t just rinse germs away. Each soap molecule has a water-attracting head and a fat-attracting tail. Those tails wedge themselves into the fatty outer membranes of bacteria and viruses, prying them apart like tiny crowbars. Essential proteins spill out, killing bacteria and rendering viruses useless. At the same time, other soap molecules break the chemical bonds that let pathogens cling to your skin, lifting them off so water can carry them down the drain.
The CDC recommends scrubbing with soap for at least 20 seconds, roughly the time it takes to hum “Happy Birthday” twice. That duration matters because the mechanical action of lathering and rubbing is what gives soap molecules enough contact time to dismantle pathogens and dislodge them from skin creases.
Alcohol-based hand sanitizers (at least 60% ethanol) work through a similar mechanism, destabilizing the lipid membranes of viruses and bacteria. But they can’t physically remove microorganisms from your skin the way soap and water can. Use sanitizer when a sink isn’t available, but default to soap whenever you can, especially after using the bathroom, before eating, or after being in a crowded public space.
Why Touch Matters More Than You Think
Respiratory viruses don’t just travel through the air. They land on surfaces, and some survive there longer than you’d expect. On stainless steel, one study found that virus levels took nearly five days to drop by 99.9%. On fabric like a cotton shirt, that same reduction took about 84 hours. Polyester was much faster, dropping to negligible levels within a few hours. Bank notes fell somewhere in between, at around three days.
In practice, expected levels of surface contamination from a real-world scenario (not a lab dose) become undetectable within about two days. Still, touching a contaminated doorknob or counter and then rubbing your eyes or nose is one of the most common ways people pick up infections. The fix is simple: avoid touching your face when you’re out, and wash your hands when you get home.
Sleep Is Your Immune System’s Reset Button
Cutting sleep short doesn’t just make you tired. It triggers a chain reaction that throws your immune system off balance. When you’re sleep-deprived, your brain produces more of a signaling molecule called prostaglandin D2. That molecule crosses from the brain into the bloodstream, where it causes a surge in inflammatory immune cells and a flood of inflammatory signals throughout the body, resembling what researchers have described as a “cytokine storm-like syndrome.”
This matters because inflammation isn’t the same as immune protection. A well-rested immune system responds precisely, sending the right cells to fight an actual threat. A sleep-deprived immune system is inflamed and dysregulated, more likely to overreact to harmless triggers and underperform against real infections. Most adults need seven to nine hours per night. Consistently getting less than that leaves your body in a state of chronic low-grade immune dysfunction.
Move Your Body Most Days
Regular moderate exercise is one of the most reliable ways to reduce how often you get sick and how bad it feels when you do. A study tracking over 1,000 adults through the fall and winter found that people who did aerobic activity on most days had 46% fewer upper respiratory infections (colds, sinus infections, sore throats) compared to sedentary participants. When active people did get sick, their symptoms were 41% less severe.
You don’t need intense workouts to get this benefit. Brisk walking, cycling, swimming, or any activity that raises your heart rate for 30 to 60 minutes counts. The key is consistency. Daily or near-daily movement keeps immune cells circulating efficiently and reduces the kind of chronic inflammation that weakens your defenses over time.
Manage Stress Before It Manages You
Short bursts of stress, like a job interview or a hard workout, temporarily boost certain immune functions. Chronic stress does the opposite. When your body stays in a prolonged stress response, it continuously releases the hormone cortisol. Over time, elevated cortisol changes the distribution of white blood cells in your bloodstream, pulling key immune players away from where they’re needed. Research shows that ongoing stressful life events trigger immune alterations that persist across time, creating a lasting shift in how your body distributes its defenses.
This is one reason people tend to get sick after prolonged periods of high stress, not during them. The immune system is suppressed throughout, but symptoms often emerge once the pressure eases and the body attempts to recalibrate. Practices that lower cortisol, whether that’s regular exercise, adequate sleep, time outdoors, or structured relaxation, aren’t luxuries. They’re part of staying well.
Feed Your Gut Well
A large portion of your immune activity takes place in and around your digestive tract. The bacteria living in your gut produce metabolites that communicate with immune cells both locally and throughout the body, influencing how quickly and effectively your immune system activates in response to a threat.
A diverse, fiber-rich diet supports a diverse microbiome, which in turn supports balanced immune signaling. Fermented foods like yogurt, kimchi, sauerkraut, and kefir introduce beneficial bacteria directly. Fruits, vegetables, legumes, and whole grains provide the fiber those bacteria feed on. A diet heavy in processed food and low in fiber does the reverse, reducing microbial diversity and weakening one of the immune system’s most important communication networks.
What About Supplements?
Vitamin D, zinc, and vitamin C are commonly marketed as immune boosters, but the evidence is mixed at best. A randomized controlled study gave people with mild COVID-19 either high-dose vitamin C (8,000 mg per day), zinc (50 mg per day), both, or neither. The supplement groups showed no improvement in symptoms or faster recovery compared to those who took nothing. A separate randomized trial of high-dose vitamin D in people with moderate to severe COVID showed no benefit either.
There is some evidence that vitamin C combined with zinc may slightly shorten the duration and severity of common cold symptoms, but the effect is modest. If you’re deficient in vitamin D or zinc, correcting that deficiency is worthwhile. But megadosing supplements when your levels are already normal doesn’t appear to provide meaningful protection against respiratory infections. Whole foods remain a more reliable strategy.
Breathe Cleaner Air Indoors
Many respiratory infections spread through tiny airborne particles that linger in poorly ventilated rooms. The CDC recommends aiming for five or more air changes per hour of clean air in shared indoor spaces, achieved through any combination of ventilation, open windows, or air filtration devices.
At home, the simplest steps are opening windows when weather allows, running exhaust fans, and using a portable HEPA air purifier in rooms where you spend the most time. If your home has a central HVAC system, switch the fan to “on” instead of “auto” when you have visitors, and use pleated filters replaced every three months. These measures make the biggest difference during cold and flu season, when windows tend to stay closed and people gather indoors.
Wear a Mask When It Counts
In situations where airborne illness is circulating and ventilation is poor, wearing a well-fitting mask significantly cuts your risk. A CDC study from California found that people who wore N95 or KN95 respirators in indoor public settings had 83% lower odds of testing positive for SARS-CoV-2 compared to people who wore no mask. Surgical masks reduced the odds by 66%. The study noted that comfort and consistency matter most. A mask you’ll actually wear properly offers more protection than a higher-rated one you keep pulling down.
Stay Current on Vaccines
Vaccines remain the single most effective tool for preventing specific infectious diseases. The 2025 adult immunization schedule recommends an annual flu shot for all adults, with a higher-dose version preferred for those 65 and older. Updated COVID-19 vaccines are recommended yearly, with adults over 65 advised to get two doses of the current formulation.
Beyond the seasonal shots, adults should ensure they’re up to date on tetanus and pertussis boosters (every 10 years), and adults 50 and older should receive the two-dose shingles vaccine. Pneumococcal, hepatitis A and B, and HPV vaccines are also recommended depending on age and risk factors. If you’re unsure what you’ve had, your doctor’s office or pharmacy can check your records and fill in any gaps, often in a single visit.