When you have a cough, certain foods, drinks, habits, and environmental exposures can make it last longer or feel worse. The most important things to avoid are airway irritants like strong fragrances and smoke, alcohol, lying flat at night, and foods that trigger acid reflux. Some of these are obvious, but others might surprise you.
Foods That Increase Mucus or Irritation
Histamine-rich foods can ramp up phlegm production and keep your airways irritated. The list is longer than most people expect: fermented products like yogurt, sauerkraut, and alcohol; canned fish like tuna and mackerel; strawberries; tomatoes; citrus fruits; chocolate; and ketchup. You don’t necessarily need to eliminate all of these, but if your cough is wet and productive, cutting back on the biggest offenders for a few days is worth trying.
High sugar intake is another concern. Consuming large amounts of added sugar triggers the release of inflammatory molecules throughout the body. In studies on healthy subjects, drinks containing 50 grams of fructose or sucrose raised blood markers of inflammation. While this research focuses on systemic inflammation rather than coughs specifically, fueling a low-grade inflammatory response while your body is already fighting an infection doesn’t help your recovery. Sugary sodas, candy, and sweetened juices are easy to skip for a week.
One common belief you can ignore: dairy doesn’t actually increase mucus. A well-known study deliberately infected volunteers with a cold virus and tracked their milk intake. There was no association between dairy consumption and upper or lower respiratory congestion, nasal secretion volume, or cough severity. If warm milk or tea with cream feels soothing, go ahead.
Drinks That Work Against You
Alcohol is the biggest beverage to avoid. It has a measurable diuretic effect, meaning it pulls water out of your body. For every 10 grams of alcohol you drink (roughly what’s in half a standard beer), your body produces an extra 100 milliliters of urine. When you’re dehydrated, the mucus lining your airways gets thicker and stickier, which makes coughing less effective at clearing irritants and more painful. Staying well-hydrated keeps secretions thin enough that your body can clear them naturally.
Caffeine’s reputation as a dehydrator, on the other hand, is largely undeserved. Studies show its diuretic effect only appears at very high doses and fades with regular use. Research measuring hydration through saliva found no significant dehydration from normal caffeine consumption. Coffee and tea are fine, and the warm liquid can actually soothe irritated airways. Just don’t rely on energy drinks loaded with sugar.
Acid Reflux Triggers
Acid reflux is one of the most common causes of a persistent cough, and many people don’t realize the connection. When stomach acid creeps up into the esophagus, it can irritate the throat and trigger a cough reflex, especially at night. If your cough gets worse after meals or when you lie down, reflux could be a factor.
The foods most likely to relax the valve between your stomach and esophagus (letting acid escape upward) include chocolate, mint, high-fat or fried foods, coffee, alcohol, carbonated beverages, spicy foods, and acidic foods like citrus and tomatoes. Late-night meals and bedtime snacks are also problematic because they increase acid production right when you’re about to lie flat. Eating your last meal at least two to three hours before bed makes a real difference.
Sleeping Position Matters
Lying flat on your back is one of the simplest things to fix and one of the most impactful. A supine position worsens coughing from multiple causes: postnasal drip pools in the back of your throat, stomach acid flows more easily toward your esophagus, and fluid congestion in the lungs increases with gravity working against you. Propping your head and upper body up with an extra pillow or two, or using a wedge pillow, helps mucus drain properly and keeps acid where it belongs.
Fragrances, Smoke, and Chemical Irritants
More than 60% of patients with chronic cough in one study reported that chemicals, scents, exercise, and cold air could trigger coughing episodes. Strong perfumes, scented candles, cleaning sprays, incense, and air fresheners release volatile compounds that irritate already-sensitive airways. Patients with this chemical sensitivity also experienced more eye irritation, nasal symptoms, headaches, and fatigue alongside their cough.
Cigarette smoke (including secondhand) is the most obvious irritant, but people often overlook household cleaning products and personal care items. While you’re recovering, switch to unscented products and ventilate rooms well when cooking or cleaning. Cold, dry air is another trigger, so breathing through a scarf in winter or running a humidifier indoors can help.
Exercise Intensity
The Mayo Clinic’s general rule is useful here: if your symptoms are “above the neck” only (runny nose, sneezing, mild sore throat), light exercise is usually fine, but dial back intensity. Walk instead of run. If your symptoms are “below the neck,” meaning chest congestion, a hacking cough, or an upset stomach, skip the workout entirely. Exercising with a fever, fatigue, or widespread muscle aches also risks making things worse or prolonging your illness.
A few days off won’t affect your fitness. When you start feeling better, ease back into your routine gradually rather than jumping to your usual intensity.
Over-the-Counter Cough Medications
Not all cough medicines are appropriate for every cough, and some can do more harm than good. Cough suppressants are designed to quiet a dry, nonproductive cough, but using them when you have a wet, mucus-producing cough can trap secretions in your lungs and slow recovery. If you’re coughing up phlegm, your body is doing exactly what it needs to do.
For children, the stakes are higher. The FDA has warned against using over-the-counter cough and cold products in children under two due to serious side effects. The American Academy of Pediatrics has advised against two of the most common cough-suppressing ingredients for children of any age, citing no well-controlled evidence that they work in kids. In the UK, regulators discourage cough and cold remedies for children under six entirely, and recommend trying basic care measures first for children aged six to twelve before reaching for medication.
For adults, recent evidence suggests that codeine-based cough medicines may be ineffective for coughs caused by the common cold, despite their long history of use. If your cough lingers beyond three weeks or produces blood, colored mucus, or wheezing, that’s worth a medical evaluation rather than another trip to the pharmacy aisle.