5 surprising symptoms of adult-onset asthma

About 25 million Americans have asthma. While most people are diagnosed before age five, one in 12 is diagnosed as an adult.

The peak years for the onset of asthma in adulthood are between 45 and 50, said Richard F. Lockey, MD, director of the Division of Allergy & Immunology at University of South Florida College of Medicine to Reader's Digest. Whenever asthma is diagnosed in adults over 20, it's typically known as adult-onset.

If you're not familiar with the condition, asthma is a disorder of the lungs that causes swelling or inflammation of the airways, production of large amounts of mucus, and muscle contractions surrounding the airways. Coughing and difficulty breathing are usually the first symptoms asthmatics notice, but they usually don't show up alone, or sometimes at all.

Below, a few surprising signs you could have asthma. Talk to your doctor if you notice any of the following:

1.You have trouble sleeping. People with asthma often suffer from nighttime coughing, wheezing, and breathlessness that disturb their sleep, according to the National Sleep Foundation. Researchers use the term "nocturnal asthma" to describe the phenomenon of asthma symptoms worsening at night. If you wake up struggling to breathe in the middle of the night, it could be a sign of asthma.

2.You hyperventilate. While it only happens in 29 percent of people living with asthma, dysfunctional breathing could be a symptom. The normal respiration rate for an adult at rest is 12 to 20 breaths per minute, and anything over 25 beats per minute is considered abnormal, according to the Cleveland Clinic.

3.You struggle to make it through your usual workout. You might not be as out of shape as you think. More than 10 percent of the general population and up to 90 percent of people previously diagnosed with asthma have exercise-induced bronchoconstriction, says a study published in American Family Physician. Exercise-induced asthma basically means your airway constricts when you work out, leading to coughing wheezing, and chest tightness. But some athletes will just become fatigued and not perform as well.

4.You sigh or take deep breaths a lot. This could be an early sign of asthma. Taking a deep breath involves the lungs expanding to full capacity. Because asthma constricts air flow, your body might unconsciously sigh to get excess air in or out, says Healthline.

5.You have allergies. Many people with asthma have allergies, which trigger asthma symptoms, according to the American Academy of Allergy Asthma & Immunology. Common allergens include house dust mites, mold, pollen, and animals. An allergist can confirm the diagnosis and help you avoid your triggers.

Sinclair Broadcast Group is committed to the health and well-being of our viewers, which is why we initiated Sinclair Cares. Every month we'll bring you information about the "Cause of the Month," including topical information, education, awareness, and prevention. May is Allergy and Asthma Awareness Month.