Is it a cold, sinus infection or allergies? How to tell the difference

It can be tough to tell the difference between a cold, a bacterial sinus infection and allergies. In fact, that’s probably one of the questions people ask doctors most frequently in this country. There’s a lot of confusion about what the signs are for these conditions—from patients and their doctors alike.

Recognizing the variations between these three conditions is important. The treatment strategies for a cold are unlike those for a bacterial sinus infection. And treatment for allergies is different still than treatment for the other two.

Let’s go through the symptoms that people often are confused about, as well as the process of deciding which condition a patient may have and what we need to do about it.

Common symptoms of colds, sinus infections and allergies

Many people have been told that the following symptoms are signs of a bacterial sinus infection as opposed to a cold:

  • Facial pain and headache
  • Discolored mucus or sinus drainage
  • Severe nasal congestion
  • Fever (usually above 101 degrees)

But in reality, these symptoms don’t help us distinguish one condition from the other, at least in the first week to 10 days. Generally speaking, all of the “classic” symptoms of a sinus infection can be present in a cold.


All of the “classic” symptoms of a #sinusinfection can be present in a cold. via @MedStarWHC

If you’ve had these symptoms for fewer than seven to 10 days, they’re almost certainly signs of a cold virus. When people have these symptoms for more than seven to 10 days without improvement, that’s when we start thinking it might be a bacterial sinus infection. It is also very unusual for a cold, or other viral upper respiratory illness, to worsen after five days. This suggests a transition to a bacterial process. This is important because antibiotics should only be used when a bacterial process is suspected.

The symptoms of allergies don’t normally include fever or a lot of discolored sinus drainage. Classic allergy symptoms may include:

  • Cough
  • Nasal congestion/stuffiness
  • Itchy ears
  • Itchy, watery eyes
  • Runny nose, usually clear
  • Scratchy or low-grade sore throat
  • Sneezing

Some of these are similar to cold or sinus symptoms. The difference is that allergy symptoms don’t follow the course of a cold, which runs through its symptoms as the cold progresses. Allergy symptoms are more consistent than cold symptoms. There is often a pattern to the symptoms related to a change in the indoor or outdoor environment (seasonal changes, exposure pets, mold, etc.).

But people with chronic allergies over long periods of time may not have these symptoms, especially adults. These patients are more likely to have nasal congestion and post-nasal drip, much like the symptoms of a “chronic sinus infection.” Like many illnesses or life stresses, allergies can also be associated with significant fatigue.

If you have sinus infections frequently or you have chronic (persistent or long-standing) upper-respiratory symptoms, it’s often tempting to think you know what’s wrong based on the symptoms. It can be easy to mistake one condition for another if all we go on are the symptoms.

Somebody might treat “bad allergies” for months and months because of nasal congestion or blockage on one side and not get any better. Eventually, this person could find that they have a persistent sinus infection, or far less likely, a nasal tumor or some other serious condition.

Related reading: The top 3 symptoms mistaken for allergies

In general, if you have unexplained symptoms that last more than two or three weeks, talk to a doctor. It doesn’t necessarily have to be a specialist like me first. You certainly could start with your primary care doctor whenever possible.

Talk to one of our doctors about your symptoms and what the right treatment options are.

Taking the right medication for the right illness

The best thing to do for cold or sinus symptoms during the first seven to 10 days is to treat the symptoms, not the illness. You can do this with medications such as:

  • Cough medicine
  • Decongestant or saline spray for nasal congestion
  • Pain reliever

Cold viruses don’t respond to antibiotics, so taking them during the first seven days probably won’t help. In fact, taking antibiotics when they’re not needed can increase your risk for being infected with antibiotic-resistant bacteria, or other serious antibiotic related problems.

After seven to 10 days, when the symptoms are more likely to indicate a sinus infection, it may be time to ask your doctor about antibiotics. However, sinus infections can and do sometimes go away on their own, just like colds. Ask your doctor if you need an antibiotic or if the infection is likely to go away on its own without medication.

If your symptoms point to allergies, many effective medications are available over the counter to control symptoms, such as antihistamines and nasal steroid sprays. These medications work on all sorts of allergies because they suppress the body’s reactions to allergens, rather than treating the specific allergen. Some antihistamines can cause drowsiness, however, so be cautious of that when taking them. They also do not help stuffiness or pressure symptoms, so adding a decongestant plus a pain reliever as needed can help you “ride it out.”

Avoiding what ails you

Of course, the best option would be to not get sick in the first place if possible. You can help your immune system fight off viruses and infections by doing the following:

  • Get enough sleep. Most adults need at least seven hours of sleep per night.
  • Maintain a healthy diet and weight. Diets high in fruits, vegetables and whole grains and low in saturated fat are best.
  • Drink plenty of fluids (alcohol and caffeine don’t count)—dryness is the enemy of a healthy respiratory system.
  • Stop smoking. Smoking lowers the body’s immune response and makes it more vulnerable to viruses, as well as much more serious risks. Our Pulmonary Services team offers smoking cessation services if you need help to quit smoking.

Minimize your risk for catching cold viruses by avoiding people who have colds. If you have to be around them, try not to touch them without washing your hands immediately afterward. This can eliminate cold viruses before they cause sickness. If you have a cold, try to avoid close contact with other people for a few days to minimize the chance of them getting sick. If you must be around others, cough or sneeze into your elbow instead of your hand to reduce the virus’ spread.

Bacterial sinus infections aren’t contagious, so you don’t have to worry about being around someone who has one. However, the general tips listed above can help the body better fight off the bacteria that cause sinus infections before you get sick.

As for allergies, it’s a good idea to avoid known allergens if possible. Sometimes that’s not practical. Make sure to follow your doctor’s advice for reducing or eliminating your allergy exposure, and use allergy medications to keep symptoms under control.

It’s easy to mistake the symptoms of a cold for those of a sinus infection or vice versa. And it’s tempting to think we know what’s wrong with us based on how we’ve felt before. Be patient, and talk to your doctor about your symptoms. A little caution and the right plan can help you feel better fast—without taking medication you don’t need to treat an illness you may not have.

The top 3 symptoms mistaken for allergies

I see hundreds of people every year who ask for help controlling their allergy symptoms. Allergies can be serious and even life-threatening in some cases. But at least half of the patients I see for ear, nose and throat allergy symptoms don’t have allergies at all.

It’s a common mistake to make. Symptoms like nasal obstruction, “post-nasal drip,” runny nose and cough also may be caused or contributed to by other conditions having nothing to do with allergies.

Good treatment sometimes requires that we determine exactly what’s causing a person’s symptoms. That way, we can prescribe the right treatment for the right problem. Let’s examine the top three problems patients commonly mistake for allergy symptoms or sinus infections and see the impacts they can have on sufferers.

Symptom 1: Nasal obstruction

Nasal obstruction, or a blockage of the nasal airway, is a common symptom of allergies and sinus infections. But the anatomy of the nose, or the way the nose is shaped, can have a major effect on a person’s ability to breathe easily.

Deviated septum

The nasal septum is the thin, wall-like structure that separates the right and left nostrils in the nose. Ideally, the septum is straight to divide the nostrils evenly. But birth defects, injuries to the nose or even rapid growth during puberty can cause the septum to become crooked, or deviated.

Most of us have septums that are less than perfectly straight, but it’s usually not noticeable. For some people, though, a deviated septum, depending on its shape, may lead to an obstruction of one or both nostrils.

A nasal steroid may be prescribed, or, in more severe cases, we can correct a deviated septum through a surgical procedure called a septoplasty.

Learn about our minimally invasive ear, nose and throat surgical options.

Swollen turbinates

The turbinates are another structure of the nose. They’re located on either side of the septum inside the nostrils. The turbinates filter, warm and humidify air and keep it from being too dry as you breathe in.

If the turbinates are too large (a condition called turbinate hypertrophy) or misshaped, they can block the airway in the nose. This can lead to a similar type of nasal obstruction as one caused by a deviated septum, and the conditions can also occur together. Someone who has turbinate hypertrophy can feel like they have a stuffy nose or trouble breathing all the time.

A nasal steroid may decrease inflammation (and therefore, the swelling) of the turbinates, or surgery can be performed to decrease their size.

Symptom 2: Chronic cough and sore throat

Allergies or sinus infections can be associated with other inflammatory symptoms, such as:

  • Chronic coughing
  • Hoarseness, or a harsh, strained or raspy voice
  • Sore throat

But these also can be symptoms of other problems, such as chronic acid reflux. Acid reflux occurs when stomach acid backs up, or refluxes, out of the stomach and into the esophagus. The chronic type of acid reflux is called gastroesophageal reflux disease, or GERD. In some cases of GERD, referred to as laryngopharyngeal reflux (LPR), stomach contents can back up and cause symptoms all the way up into the throat, which can damage the soft tissues in that area. LPR can lead to coughing, hoarseness or sore throat, which could be mistaken for allergy symptoms or signs of a sinus infection.

Symptom 3: Headache and facial pain

I frequently see people who come in complaining of “sinus headaches.” They have “congestion” all the time. They have debilitating pain on one or both sides of their head and face and are sensitive to bright lights.

Some of these people actually do have sinus infections or other sinus conditions, but others don’t. Many people who think they have sinus conditions actually are undiagnosed migraine sufferers.

Many people who think they have sinus headaches actually are undiagnosed migraine sufferers.

When I bring this up to patients, some don’t believe me at first. They’ve never considered that their symptoms might be caused by migraine. They say things like, “I’m not seeing sparkly lights or an aura. I didn’t throw up. Aren’t you supposed to throw up if you have a migraine?” That’s not always the case.

I start thinking of migraine whenever I see a patient who complains of sinus headaches but who doesn’t have any other symptoms relating to the sinuses or nasal cavity, such as abnormal nasal drainage or obstruction. If you think you have frequent sinus headaches or infections, but you don’t have nasal symptoms like obstruction, abnormal drainage or other upper respiratory symptoms, ask your doctor if you might actually have migraine.  

Smoking: A major contributor to mistaken allergy symptoms

Symptoms of upper-respiratory conditions are a common thread among people with allergies: runny noses, coughing, sore throats, hoarseness, etc. But those are also symptoms we associate with irritation from first- or second-hand smoke. Smoking contributes to many upper-respiratory conditions patients often think of as allergy symptoms. 

Smoking contributes to many upper-respiratory conditions patients often think of as allergy symptoms.

One of the things we ask during a routine allergy examination is whether the patient smokes or lives with a smoker. It’s surprising how many people don’t know or haven’t accepted that their smoking is the cause of their problems.  

When I see a patient for allergy symptoms, and I learn that the patient smokes, I always begin by recommending that the patient stop smoking. It often can resolve the respiratory problems that brought them to see me in the first place. And even if smoking isn’t the root cause of the problem, it’s often very difficult for us to deal with the issue while the body is under constant respiratory distress from the person’s smoking.

Find the root cause of symptoms to get lasting relief

Allergies are a common condition, and they’re easy to misdiagnose. Most patients don’t need full skin or lab testing for allergies, so doctors often make a diagnosis based on patients’ symptoms, which can be similar to those of other conditions.  

People often assume they have allergies based on a Google search of their symptoms without checking with a doctor. Or they dismiss allergies or sinus problems as something not worth caring about; they just want relief from the symptoms that are interfering with their lives. Talk to your doctor about chronic symptoms, even if you think you know what’s causing them.  

My job as a doctor is to get to the root of what’s harming my patients. If that’s an allergy or a sinus condition, we have treatments available to address those problems. But these symptoms could be signs of more serious issues. If allergy or sinus treatments aren’t giving you relief, talk with your doctor about other potential causes of your symptoms to make sure you’re getting to the root cause—and treating it appropriately.