Most common illnesses, like colds and stomach bugs, resolve on their own within a few days to a week. You can’t force your body to clear a virus instantly, but you can create the conditions that let your immune system work as fast as possible. That means prioritizing sleep, staying hydrated, managing your worst symptoms, and eating when you’re ready.
Why You Can’t Skip the Wait
When your body encounters a virus for the first time, the full immune response takes several days to ramp up. Your immune cells need time to identify the invader, produce antibodies, and distribute them throughout your body. Cold symptoms typically peak two to three days after infection and resolve within a week. The flu tends to last longer, often five to seven days of significant symptoms with lingering fatigue afterward.
If you’ve had the same virus before, your immune system has a head start. Memory cells from previous infections can begin producing antibodies within days rather than weeks. This is why second bouts of the same illness tend to be shorter and milder, and why vaccines work.
Sleep Is the Single Best Thing You Can Do
Sleep isn’t just rest for your muscles. It’s when your immune system is most active in producing infection-fighting cells. The data on this is striking: people who sleep fewer than five hours a night are 4.5 times more likely to catch a cold than those sleeping seven or more hours. Even sleeping five to six hours raises the risk more than fourfold. Each additional hour of sleep per night has been associated with a 12% lower chance of infection.
Poor-quality sleep matters just as much as short sleep. People with fragmented, restless sleep are 5.5 times more likely to develop a cold after exposure compared to sound sleepers. If you’re already sick, this means doing whatever it takes to get long, uninterrupted sleep: darkening your room, skipping screens before bed, and taking a symptom-relieving medication at night so congestion or pain doesn’t wake you.
How to Stay Hydrated
Fever, sweating, vomiting, and diarrhea all pull water out of your body faster than normal. Dehydration makes you feel worse and can slow recovery. The goal is simple: replace what you’re losing.
For a respiratory illness like a cold or flu, sipping water, broth, or herbal tea throughout the day is usually enough. Warm liquids have the added benefit of loosening congestion and soothing a sore throat. If you’re dealing with a stomach bug that involves vomiting or diarrhea, you’re losing electrolytes (sodium, potassium) along with water, and plain water won’t fully replace them. A premixed oral rehydration drink or a diluted sports drink works better in this case.
If vomiting makes it hard to keep fluids down, start small: about a tablespoon every five minutes, gradually increasing as your stomach settles. For each bout of diarrhea, try to drink an extra cup (about 240 mL) to compensate.
Managing Symptoms So You Can Rest
Fever, aches, and congestion aren’t the illness itself. They’re your immune system’s response. A moderate fever actually helps your body fight infection, so you don’t necessarily need to bring it down unless it’s making you miserable or keeping you from sleeping. When you do want relief, acetaminophen and ibuprofen are the two main options.
You can use either one on its own, or combination products contain both. If you’re using a combination tablet, the standard adult dose is two tablets every eight hours, with a maximum of six tablets per day. Don’t exceed 4,000 milligrams of acetaminophen in 24 hours from all sources combined, including any cold medicines that may also contain it. Avoid alcohol while taking acetaminophen, as the combination stresses your liver. If you have a history of stomach ulcers, kidney disease, or heart problems, ibuprofen may not be safe for you.
For congestion, a saline nasal spray or rinse helps thin mucus without medication. A hot shower or a bowl of steam serves a similar purpose. Over-the-counter decongestant sprays work quickly but shouldn’t be used for more than three consecutive days, as they can cause rebound congestion.
A sore throat often responds well to warm salt water gargling, ice chips, or throat lozenges. Honey (for anyone over age one) can soothe a cough and coat an irritated throat.
What to Eat When You’re Sick
You don’t need to follow a restricted diet or force yourself to eat if you have no appetite. Current medical consensus is that dietary restrictions don’t help treat viral illness. When your appetite returns, go back to eating normally, even if you still have some diarrhea.
That said, certain foods can make symptoms worse, especially with a stomach bug. Caffeine, high-fat or greasy foods, very sugary drinks, and dairy products tend to aggravate nausea and diarrhea. Some people have trouble digesting lactose for up to a month after a stomach illness, so if milk seems to upset your stomach during recovery, that’s a temporary and normal effect.
When you are ready to eat, foods rich in certain nutrients give your immune system raw materials to work with. Vitamin C, found in citrus fruits, bell peppers, strawberries, and kiwi, supports the production of white blood cells. Zinc is essential for immune cell function and comes from poultry, shellfish, red meat, and beans. Protein from any source helps your body repair tissue and build antibodies. A bowl of chicken soup checks several of these boxes at once: fluid, sodium, protein, and zinc from the chicken, plus warmth that eases congestion.
Recovering From a Stomach Bug
Viral gastroenteritis, often called the stomach flu, typically lasts one to three days. The biggest risk is dehydration from vomiting and diarrhea, not the virus itself. Focus on small, frequent sips of an electrolyte solution during the worst of it, then return to normal foods as soon as you feel able.
For infants and young children, continue breast milk or formula as usual. There’s no need to switch to a special diet. Older children and adults should eat what they normally eat once hunger returns. The old advice about sticking to bananas, rice, applesauce, and toast (the BRAT diet) is no longer recommended as a treatment, since it’s nutritionally incomplete and doesn’t speed recovery.
When You’re Well Enough to Go Back
The CDC’s current guidance says you can return to normal activities when both of these have been true for at least 24 hours: your symptoms are improving overall, and you haven’t had a fever without the help of fever-reducing medication. Meeting these criteria means you’re typically less contagious, though your body may still be shedding some virus. For the next few days after returning, wearing a mask in crowded indoor spaces and washing your hands frequently reduces the chance of passing your illness along.
Symptoms That Need Medical Attention
Most colds and stomach bugs don’t need a doctor. But certain signs mean something more serious may be going on. In adults, difficulty breathing or shortness of breath is always a reason to seek immediate care. A fever above 103°F (39.4°C) that doesn’t respond to medication, confusion or unusual drowsiness, inability to keep any fluids down for more than 24 hours, or symptoms that improve and then suddenly get worse all warrant a call to your doctor or a visit to urgent care.
In children, watch for a high fever paired with a stiff neck, back stiffness, or a change in alertness. Abnormal or labored breathing in a child of any age is a medical emergency. Infants who stop producing wet diapers for six or more hours are likely dehydrated and need professional evaluation.