Postnasal drip
Sounds like: Either a dry or wet cough. It’s caused by mucus dripping down your throat (due to either allergies or a cold), which tickles nerve endings, triggering coughing, Dr. Parsons says.
Other telltale symptoms: The cough is worse at night; there’s a tickly feeling at the back of your throat. If it’s due to allergies you may also have itchy eyes and sneezing.
Diagnosis and Rx: If you suspect allergies, try an over-the-counter antihistamine. But if that doesn’t help after a couple weeks, see your doctor, who can refer you to an allergist for skin testing. If it’s due to a residual cold, you can try natural remedies like saline washes and steam to help relieve congestion, but if the cough lingers for more than a week see your doctor to rule out a sinus infection, which might require antibiotics.
Asthma
Sounds like: A dry cough that ends with a rattle or wheeze. People with asthma have inflamed airways, which can cause difficulty breathing as well as wheezing and coughing.
Other telltale symptoms: The cough gets worse at night or while exercising; chest tightness; shortness of breath; fatigue
Diagnosis and Rx: To check for asthma, your doctor will most likely order spirometry, a lung function test, he says. To treat it, there are two types of medications: quick-relief drugs (bronchodilators like albuterol, which make it easier to breathe) and drugs you take daily to keep asthma under control, such as leukotriene modifiers (like Singulair).
GERD
Sounds like: A dry, spasmodic cough. Short for gastroesophageal reflux disease, GERD is when acid from your stomach backs up into your esophagus. It’s actually the second most common cause of chronic cough, causing about 40% of cases, according to a 2006 review published in Nature.
Other telltale symptoms: Your cough gets worse when you’re lying down or eating. “The classic sign is coughing that starts as soon as you lie down in bed at night,” says Dr. Parsons. About 75% of GERD patients with chronic cough have no other symptoms, but if you do they can include heartburn and hoarseness.
Diagnosis and Rx: Tests may include an x-ray of your upper GI tract and/or an endoscopy (where your doctor inserts a thin, flexible tube down your throat to examine it). GERD is treated with OTC or prescription meds to reduce acid production, like Pepcid AC, Zantac, or Prilosec.