Postnasal Drip: Symptoms and Treatment

Medically Reviewed by Jabeen Begum, MD on February 26, 2024
Written by Rita Colorito, Stephanie Watson, Amy Gopal
12 min read

Postnasal drip is the drainage of mucus from your nose or sinuses into your pharynx, or throat. 

Every day, glands in the linings of your nose, throat, airways, stomach, and intestinal tract produce mucus. Your nose alone makes about a quart of it each day. Mucus is a thick, wet substance that moistens these areas and helps trap and destroy foreign invaders like bacteria and viruses before they cause infection.

Normally, you don't notice the mucus from your nose because it mixes with saliva, drips harmlessly down the back of your throat, and you swallow it.

When your body produces more mucus than usual or it's thicker than normal, it becomes more noticeable.

The excess can come out of the nostrils -- that's a runny nose. When the mucus runs down the back of your nose to your throat, it's called postnasal drip. 

This feeling that something is dripping down your throat is a common symptom of conditions such as the common cold, sinusitis, and allergies. It can cause a sore throat or a cough.

Inflammation or swelling of the nasal passages can cause postnasal drip to build up. When that happens, the excess mucus, or snot, can also cause congestion. Common reasons for nasal inflammation include viral or bacterial infections, allergies, or irritants in the air.

When you're not feeling well, it's common to get postnasal drip. It can feel gross and uncomfortable. In some cases, postnasal drip may turn into a chronic cough or ongoing problem.

Mucus is mostly water, antibodies, proteins, and dissolved salts. It's your body's way of trapping dust, dirt, and other particles from entering your lungs. Color changes to your mucus may mean something is going on with your health. 

It's more common to get thick, colored mucus at the beginning of a bacterial infection. And other symptoms caused by a bacterial infection often last more than 10 days without getting better. With a viral infection, it's more common to get thick, colored mucus later, after several days. 

Clear mucus

Normal mucus is clear. It means that your nasal passages are healthy. 

In the beginning stages of a cold or allergy, you may still have clear mucus, just more of it. That extra mucus is the sign that the body is fighting off an infection or irritation.

White mucus

White or cloudy mucus is often thicker. This happens because your nasal passages become swollen or inflamed, which causes your mucus to lose moisture. White or cloudy mucus may mean you have a cold or nasal infection. 

Yellow mucus

Yellow mucus can mean your cold or nasal infection is getting worse. Both bacterial and viral upper respiratory infections can cause yellow mucus. The color comes from white blood cells that rush to the infection to try to clear it. 

An increase in the number of certain immune system cells or in the enzymes these cells produce can cause your mucus to change to yellow or green.

Green mucus

Green mucus can be a sign of a more serious viral or bacterial infection. It means your immune system is working hard to fight off the infection. Green mucus is thick with dead white blood cells.

If you still feel sick after 10 days or if you have a fever, see your doctor right away. Green mucus can mean you have sinusitis. You will need to take antibiotics to treat this bacterial infection. 

Brown mucus

Brown mucus can be a sign of exposure to pollution or smoking. It can also be caused by a bacterial infection or the presence of dried blood, which can occur from blowing your nose too hard. If your mucus is brown and you have other symptoms, see a doctor right away to rule out any serious conditions.

Heavy smokers and people with certain lung diseases are more likely to have brown or black mucus. 

Black mucus

Black mucus isn't a common color and can be a sign of exposure to very high levels of pollution or smoke. The debris can build up in your nose. 

In rare cases, black mucus can mean you have a serious fungal infection. These infections are more common in people with compromised immune systems. 

If you have other symptoms or have a compromised immune system, see your doctor right away to rule out any serious issues.

Pink or red mucus

Pink or red mucus can be a sign of bleeding in the nasal passages. Blowing or rubbing your nose too hard can cause some blood vessels to break. You may see a pinkish hue. In some cases, you may get a nosebleed. An infection can also cause your nose to bleed. If the red color is accompanied by other symptoms, see a doctor right away for treatment.

The excess mucus that triggers it has many possible causes, including:

  • Flu
  • Allergies, also called allergic postnasal drip
  • Sinus infection or sinusitis, which is an inflammation of the sinuses
  • Object stuck in the nose (most common in children)
  • Certain medications, including some for birth control and blood pressure
  • Deviated septum, which is the crooked placement of the wall that separates your two nostrils, or some other problem with the structure of the nose that affects the sinuses
  • Changing weather, cold temperatures, or really dry air
  • Certain foods (for example, spicy foods may trigger mucus flow)
  • Pregnancy
  • Sensitivity to bright lights
  • Fumes from chemicals, perfumes, cleaning products, smoke, or other irritants

Sometimes the problem isn't that you're producing too much mucus, but that it's not being cleared away. Swallowing problems can cause a buildup of liquids in the throat, which can feel like postnasal drip. These problems can sometimes occur because of a blockage or conditions such as gastroesophageal reflux disease, also known as GERD.

Postnasal drip can be a small annoyance at first. Your throat may feel scratchy. Too much mucus can also make your voice sound hoarse, or like you are gurgling. You may have an urge to constantly clear your throat. A buildup of mucus can also cause bad breath.

Over time, postnasal drip can cause a sore or irritated throat. It can lead to inflammation, which can cause your tonsils and other tissues in your throat to swell. 

It also can trigger a cough, which often gets worse at night. In fact, postnasal drip is one of the most common causes of a cough that just won't go away.

If the mucus plugs up your Eustachian tube, which connects your throat to your middle ear, you could get a painful ear infection. You could also get a sinus infection if those passages are clogged.

Postnasal drip and nausea

Nausea isn't a typical symptom of postnasal drip. But if too much mucus drains into your stomach, it can cause nausea or vomiting. 

Some people may also have nausea when taking certain medications used to treat postnasal drip symptoms such as decongestants. These medications can cause stomach upset and may lead to nausea in some individuals. If you're experiencing nausea while taking these medications, talk to your doctor about alternative treatment options.

To figure out what's causing your postnasal drip, your doctor will:

  • Ask about your medical history, including symptoms with your postnasal drip 
  • Do a physical exam of your ear, nose, and throat. 

Your doctor may refer you to an ear, nose, and throat (ENT) doctor, called an otolaryngologist. The ENT doctor may recommend a nasal endoscopy. This procedure looks inside your nasal cavity and the openings of your sinuses using a special device called an endoscope -- a thin flexible tube with a camera and a light. They may also order imaging tests such as X-rays. 

If your doctor thinks allergies are causing your postnasal drip, they may refer you to an allergy doctor for testing and treatment. 

How you treat postnasal drip depends on what's causing it. 

Over-the-counter medications

Antihistamines and decongestants can often help with postnasal drip caused by sinusitis and viral infections. They also can be effective, along with steroid nasal sprays, for postnasal drip caused by allergies.

The older, over-the-counter (OTC) antihistamines, including diphenhydramine (Benadryl) and chlorpheniramine (Chlor-Trimeton), might not be the best choices for postnasal drip. When they dry out mucus, they can actually thicken it. They also may make you drowsy. 

Newer antihistamines may be better options and are less likely to cause drowsiness. They include:

It's a good idea to check with your doctor before taking these because all of them can have side effects that range from dizziness to dry mouth.

Oral decongestants, such as pseudoephedrine (Sudafed), can shrink swollen blood vessels and tissues in your nasal and sinus passages. This can help unblock a stuffy nose and cause fewer postnasal drips. 

OTC corticosteroid nasal sprays can also help. They include:

Nasal spray decongestants containing oxymetazoline (Afrin or Vicks Sinex) can often stop postnasal drip more quickly. But these should be taken for no more than a couple of days. Anything longer than that can create a rebound effect, making your congestion worse.

Prescription medication

If OTC medications don't help, you may need a prescription medication. If postnasal drip is caused by a bacterial infection, antibiotics can help clear up the infection and stop the drip. 

Antibiotics don't work on colds and other viral infections.

Prescription medications for postnasal drip may include nasal sprays like beclomethasone and ipratropium (Atrovent).

Deviated septum surgery

In cases where a deviated septum causes postnasal drip, surgery to straighten your septum, called a septoplasty, leads to better airflow. It's a more permanent solution to postnasal drip. 

Other methods

Postnasal drip can also cause mucus buildup. To thin out your mucus, you can use saline or medicated nasal sprays. You can also take a mucus-thinning medication such as guaifenesin (Mucinex).

For centuries, people have treated postnasal drip with all kinds of home remedies. Probably the best known and most loved is hot chicken soup.

While it won't cure you, hot soup or any hot liquid might give you some temporary relief and comfort. It works because the steam from the hot liquid opens up your stuffy nose and throat. It also thins out mucus. And because it's a fluid, the hot soup will help prevent dehydration, which will make you feel better, too.

Because postnasal drip can cause thick mucus, keeping it thin can help relieve symptoms. Thick mucus is stickier and more likely to bother you. Keeping mucus thin helps prevent blockages in the ears and sinuses. A simple way to thin it out is to drink more water.

Other home remedies

To manage postnasal drip and the thick mucus it causes:

  • Take a hot, steamy shower.
  • Prop up your pillows at night so that the mucus doesn't pool or collect in the back of your throat.
  • Use a nasal irrigation, such as a neti pot, to flush mucus, bacteria, allergens, and other irritating things out of the sinuses.
  • Use a vaporizer or humidifier to add moisture in the air.

Postnasal drip is a common symptom of many respiratory and cold viruses. But with more than 200 cold viruses, it can prove difficult to prevent catching a cold. Viruses can spread through the air and can linger on surfaces that you touch every day. But there are some things you can do to lower your risk of getting sick, or developing postnasal drip.

Wash your hands

To prevent the spread of germs, wash your hands before and after:

  • Preparing food
  • Eating food
  • Caring for someone who is sick, especially with vomiting or diarrhea
  • Treating a cut or wound

Also wash your hands after:

  • Blowing your nose, coughing, or sneezing. If possible, cough or sneeze into your elbow, to help prevent the spread of germs to others.
  • Using the toilet
  • Changing diapers or cleaning a child who has used the toilet
  • Handling pet food/treats and pet waste
  • Touching garbage
  • Touching an animal, animal feed, or animal waste

Get vaccinated

Get recommended vaccines, such as the flu and COVID-19 vaccines, to help prevent you from getting sick with a virus in the first place.

Prevent allergies

If you have allergies, you can take OTC allergy medication before spring allergy season to help prevent postnasal drip. 

Cromolyn (Nasalcrom) is an OTC nasal spray that helps prevent allergy symptoms in your nose. It reduces runny nose and postnasal drip. Cromolyn isn't an antihistamine, so it doesn't provide immediate relief of symptoms. It takes 1 to 2 weeks to work and for best results should be taken before allergy season starts. 

Your doctor may also recommend immunotherapy, or allergy shots, to prevent allergy symptoms before they start.

You can also prevent seasonal and other allergies, including indoor allergens, by reducing your triggers:

  • Cover your mattresses and pillowcases with dust-mite-proof covers.
  • Wash all sheets, pillowcases, and mattress covers often in hot water.
  • Use special HEPA air filters in your home. These can remove very fine particles from the air.
  • Dust and vacuum regularly.

Most people experience postnasal drip at some point. It's a common symptom of colds, allergies, and infections. Most of the time, you can treat postnasal drip with OTC medications and at-home remedies. If you keep getting postnasal drip, or it doesn't go away and you have other symptoms, see your doctor to find out the cause and best way to treat it.

Call your doctor if:

  • Your postnasal drip smells bad.
  • You have a fever.
  • You start wheezing.
  • Your symptoms are severe or last for 10 days or more.

These may be signs that you have a bacterial infection. And let your doctor know right away if you notice blood in your postnasal drip.

If medication doesn't relieve your symptoms, you might need to see an ear, nose, and throat (ENT) specialist (also called an otolaryngologist) for evaluation. Your doctor might want you to get a CT scan, X-rays, or other tests.

Postnasal drip is a common symptom of allergies, nasal irritants, and bacterial and viral infections that causes your nose to increase mucus production. The excess mucus then drips down the back of your throat. Postnasal drip causes other symptoms, including a sore throat, hoarse voice, lingering cough, and bad breath. If your postnasal drip gets worse, doesn't get better after 10 days, or you have a fever with it, see your doctor. They can help figure out what's causing it and how best to treat it. 

What does postnasal drip feel like?

Your nose makes about a quart of mucus every day. Most of the time, you don't feel it because it mixes with saliva and you swallow it unnoticed. But when you have a nasal irritant or infection, your nose can produce more and thicker mucus. Postnasal drip feels like liquid dripping in the back of your throat. As the mucus builds up, it can make you feel congested or stuffed up. It can also feel like a sore, scratchy, or tickly throat.

What is the best over-the-counter medicine for postnasal drip?

There are several types of OTC medicines that can treat postnasal drip. But what works best will depend on what's causing your postnasal drip. Your doctor or pharmacist can help you choose one that's right for you and your symptoms.

What allergies cause postnasal drip?

Any allergy or irritant to your nose can cause a runny nose and increase postnasal drip. Examples are dust allergies or seasonal pollen allergies.

Why won't the mucus in my throat go away?

Mucus buildup can become thick, so it may take time to clear up. To help thin out thickened mucus, try using medicated or saline nasal sprays. An irrigation device called a neti pot can also flush out thick mucus. A hot steam shower can also help moisten your nasal passages and relieve congestion. You can take medication called guaifenesin (Mucinex) to thin out mucus. Sometimes when mucus builds up it can cause a bacterial infection, and you'll need antibiotics to help clear it up. 

Does Flonase help with postnasal drip? 

Flonase is an OTC steroid nasal spray that treats sneezing, itchy, or runny nose caused by seasonal allergies. It can help stop a runny nose and postnasal drip.