If you’re a seasonal allergy sufferer (more than 50 million Americans are), you probably already have a few tricks to avoid triggers, like not running outside when pollen counts are sky-high or keeping the windows closed in favor of the AC. But you may not know about these less obvious factors that can make symptoms worse. Here are 9 things making you miserable—and how to fight back. (For more cutting-edge health tips delivered straight to your inbox, !)

1. Stressful work deadlines

Researchers at Ohio State University College of Medicine found that allergy sufferers had more symptoms after they took an anxiety-inducing test, compared with when they performed a task that did not make them tense. Stress hormones may stimulate the production of IgE, blood proteins that cause allergic reactions, says study author Janice Kiecolt-Glaser, PhD. If you’re under stress, get enough sleep. A sleep deficit can worsen both allergy symptoms and stress, she says. Check out these 100 simple strategies to sleep better every night. (If you feel like you're suffering from seasonal affective disorder, there is a promising new treatment you can read about from Prevention Premium.)

2. An extra glass of wine with dinner

Alcohol can raise the risk of perennial allergic rhinitis by 3% for every additional alcoholic beverage consumed each week, Danish researchers found. One potential reason: Bacteria and yeast in the alcohol produce histamines, chemicals that cause telltale allergy symptoms like stuffy nose and itchy eyes.

Avoid alcohol when your symptoms are acting up, says Richard F. Lockey, MD, director of the division of allergy and immunology at the University of South Florida College of Medicine. (Do you overdo it on the vino? Here are 6 sneaky signs you drink too much.)

preview for Your Body on Alcohol

3. Waiting too long to take meds

Medications that block histamines work best before you’re even exposed to allergens, says allergist James Sublett, MD, a spokesperson for the American College of Allergy, Asthma, and Immunology. Start medication a couple of weeks before the season commences or before you’ll be around allergens (if you react to grass, before a golf game, for example).

4. A not-hot-enough washing machine

If you find yourself sniffling in bed, crank your washing machine to the hottest setting.

In a South Korean study, laundering cotton sheets at 140°F killed 100% of dust mites, while a warm 104°F wash destroyed just 6.5%. A machine's "sanitize" setting is likely hot enough; check the manual if your model lacks this option. (Make sure when it comes to laundry, you aren't making this super-common mistakes.) Some units heat water internally, but others use what flows through the pipes, so you may need to boost your water heater. (Caution: This temp can scald in 5 seconds.)

5. Houseplants that make you sneeze

Your innocent orchid could bring tears to your eyes. More than 75% of hay fever sufferers are allergic to at least one common houseplant, found a Belgian study. Allergens in plant sap can diffuse into the air and set off your sniffling. Though any potted greens can be trouble, researchers found that ficus, yucca, ivy, palm, orchid, and fern varieties are most irritating to allergy-prone people.

6. Skipping medication in the evening

One time not to forget your allergy meds? Before bed—so the medication will be circulating in your bloodstream early the next day. Symptoms such as sneezing, weepy eyes, and runny nose peak in the morning, says Richard J. Martin, MD, chair of the department of medicine at National Jewish Medical and Research Center in Denver. Choose regular (instead of nondrowsy formulas) for extra help falling asleep promptly.

7. Water workouts in an indoor pool

Chlorine-filled lap lanes can wreak havoc on your system. Used to disinfect, chlorine is highly irritating to the skin, eyes, and respiratory tract, says . And a recent study in the journal Pediatrics found that teens who log more than 100 hours in a chlorinated pool have a 3 to 7 times higher risk of developing hay fever, compared with swimmers who dunk in chlorine-free pools.

To reap the benefits of your water workout without wheezing and sneezing, consider wearing a mask or goggles when swimming to protect your eyes from chlorine's temporarily irritating effects. Try to swim in outdoor pools, where the gas is more readily dispersed, instead of indoor ones, and avoid swimming in chlorinated pools daily. (While you're in there, try this fat-blasting water workout.)

8. Friends who smoke

Cigarettes—with their numerous toxic chemicals and irritants—are nasty for everyone, but allergy sufferers may be especially sensitive, according to the National Institute of Environmental Health Sciences. In fact, one Japanese study of teenage students found that more than 80% of those who came from homes where family members smoked heavily showed signs of nasal allergies.

Even if you don’t hang around smoky bars or other areas, particles on the clothing of smoking friends or coworkers can pollute the air in your home or office.

9. Showering in the AM only

Hay fever sufferers would benefit from a quick rinse as soon as they get home from work or after being outside for a while, says allergist Stanley Fineman, MD, a physician at the Atlanta Allergy and Asthma Clinic. That’s because hidden pollen particles can get trapped on your body, hair, clothes, and shoes—continuing to trigger symptoms after you’ve returned indoors.

If you’re prone to pollen allergies, slip off your shoes, throw your clothes in the hamper, and shower as soon as you get home to avoid dragging particles all over your home. (Here are even more solutions for seasonal allergy sufferers.)