Spring allergies may grab most of the attention, but ragweed is now causing misery for up to 50 million Americans—and it will continue setting off symptoms into the fall.

Allergies are extremely common, with about 40 percent of adults worldwide afflicted, according to the American Academy of Allergy, Asthma & Immunology (AAAAI).

But it's still possible that your condition is really something else. It’s not always clear when allergies or a different condition are the cause of uncomfortable symptoms, especially in older adults.

“As you age, you often have other health problems and/or you may be taking medications that can make it more difficult to determine what’s causing your symptoms,” says Anju Tripathi Peters, M.D., an allergist and a professor of medicine and otolaryngology at the Feinberg School of Medicine at Northwestern University.

Here are the truths behind some common allergy myths.

Myth: We Outgrow Allergies Over Time

The real deal: Not necessarily. Allergies occur when your immune system overreacts to the presence of “invaders” such as pollen, mold, and dust mites. Your system releases compounds that can cause inflammation, excess mucus, and itchiness in your eyes, ears, and throat.

As you age, your immune system may become less robust and less likely to react so strongly to allergens.

“There’s a common perception that as you get older, allergies go away,” says Richard F. Lockey, M.D., an allergist and director of the allergy and immunology department at the University of South Florida College of Medicine. “There’s some truth to that. But as we see people staying healthy longer into old age, we still see people in their 80s having symptoms or developing new allergies.” 

Myth: It's Easy to Tell Allergies From Other Conditions

The real deal: It's not always easy to determine allergy causes. For example, allergic rhinitis (hay fever) affects up to 11 percent of those 66 and older, but it can be tricky to pinpoint in that age group.

“Many older people have general nasal stuffiness,” Lockey says, “whether it’s from drugs for high blood pressure or prostate problems, or just from normal age-related changes in the nasal passages.”

So be specific with your doctor about symptoms and when they appear. For instance, itchiness of the eyes, ears, or throat is a classic sign of allergies but usually doesn’t accompany respiratory infections such as colds or flu.

If symptoms crop up at certain times of the year or only when you’re around the family pet, that’s another sign you’re probably dealing with an allergic condition.

In addition, while respiratory infections can cause fever, aches and pains, or yellow mucus, allergies generally don't. And respiratory infections resolve in a week or two, while allergies may persist for longer.

Myth: Allergic Skin Problems Are Usually Seen Only in Children

The real deal: It's true that allergic skin issues such as eczema are common in children. According to the National Center for Health Statistics, 12.5 percent of youngsters experienced skin symptoms between 2009 and 2011 (the last year for which statistics were available), up from the 7.4 percent from 1997 to 1999. Children between birth and age 4 are the most prone to allergic skin reactions.

But allergy-related skin problems can affect people later in life too. In fact, according to a review in Clinical and Translational Allergy, contact allergies—which can cause redness, itching, welts, rashes, and/or hives after touching an allergen—occur more frequently as we age. Typical allergy causes include metals like nickel, perfume, plants such as poison ivy, and latex.

Important to know: Hives can erupt suddenly as a result of any type of allergy, but they can also signal the serious, systemic allergic reaction called anaphylaxis. (See “Treating Allergies Right,” below.) If you have hives and your lips, tongue, or throat feel like they’re swelling, or you’re wheezing, having trouble breathing, or becoming dizzy, call 911. Use an epinephrine injector if you’ve been prescribed one.

Myth: Food Sensitivities Are Food Allergies

The real deal: Not true. A food allergy is an immune-system reaction that can involve multiple organs and systems, and can sometimes be serious enough to cause anaphylaxis. A food sensitivity is most often limited to your digestive system.

With a true food allergy, your body has made antibodies—which combat substances the body sees as threats—against one or more proteins in that particular food, says Ravi Viswanathan, M.D., an assistant professor in the division of allergy and immunology at the University of Wisconsin School of Medicine and Public Health.

“Every time you eat it, you get hives, swelling, maybe wheezing, chest or throat tightness, shortness of breath, GI symptoms, or dizziness,” he says.

Those with sensitivities, he explains, tend to have gastrointestinal discomfort such as queasiness and bloating, but not necessarily each time they consume a problem food.

If you suspect you have a food allergy or sensitivity, keep a food and symptom diary to share with your doctor. This can help you isolate potential offenders.

Myth: Allergy Tests Are the Only Way to ID Allergens

The real deal: Not everyone with allergy symptoms needs testing to determine allergy causes, and the results should be seen as only part of the diagnostic picture. A medical history, physical exam, and discussion with your doctor about symptoms and lifestyle habits are also essential.

Allergy tests may be warranted if your doctor can’t determine what’s causing your problem. Testing can be done a couple of ways. With skin testing, an allergist or immunologist applies tiny amounts of possible allergens to pricked skin or injects them under skin (intradermal testing).

If you’re allergic to a substance, your skin will redden, swell, and/or itch within 20 minutes. (For contact allergies, you might be asked to wear a patch containing a potential allergen for two days.)

A research review published in Allergy, Asthma & Clinical Immunology found that skin-prick tests, usually done on a forearm or the back, can accurately identify the presence or absence of most allergens. (There’s not enough data to draw a conclusion about intradermal tests.)

However, a 2014 study in the Annals of Allergy, Asthma & Immunology suggests that sun damage and thinning skin may blunt the reaction to allergens, which could prevent a proper diagnosis.

Alternately, your doctor may draw your blood and order a laboratory test to identify your allergens. Blood tests may be more likely to find allergies where there are none. But doctors sometimes prefer them for those who have a skin condition like eczema or use medication that can interfere with skin tests.

Skin and blood tests for food allergies appear to be incorrect about half the time, so it’s best to use them only for foods you already suspect are triggers for you.

“We recommend against indiscriminate testing because there’s a good chance you could test positive when you’re not really allergic,” Viswanathan says. “We test only for the specific foods that seem to be causing a problem.”

If you test positive for a food allergy, your doctor may follow up with an oral challenge, where you eat the food in increasing amounts (under medical supervision) to gauge your response.

Skip the tests you might see advertised on the internet that analyze your hair or your muscle response to allergens. They’re not backed by quality research or evidence. 

Treating Allergies Right

If you know you have allergies, start by avoiding triggers:

Ragweed: Check local pollen levels and try to stay inside when they’re high.

Mold: Avoid leaf piles, ventilate damp rooms, and fix leaks promptly.

Dust mites and pet dander: Keep pets out of the bedroom, vacuum regularly with a low-emission vacuum (see our vacuum cleaner buying guide here), cover mattresses and pillows with allergen-proof cases, and wash bedding in hot water.

For more relief, consider:

 An over-the-counter antihistamine to reduce symptoms: Newer drugs such as cetirizine ((Zyrtec), fexo-fenadine (Allegra), and loratadine (Claritin)—all available as generics, too—are less likely to cause drowsiness than older drugs.

 Steroid nasal sprays: OTC and prescription products such as fluticasone (Flonase and generic) and triamcinolone (Nasacort and generic) can keep symptoms at bay but can also cause nasal irritation.

 Immunotherapy: For more bothersome symptoms, your doctor might recommend regular injections or daily sublingual tablets (only for grass and ragweed) that contain small amounts of the offending substances. This should gradually desensitize you to allergens.

Emergency epinephrine: If you’re at risk of anaphylaxis, a potentially life-threatening reaction to a food, insect sting, or other allergen, you need to have injectable epinephrine (Adrenaclick, EpiPen) on hand.