Common Cold and Flu Complications

The common cold and the flu typically last about a week. But if your symptoms have lasted longer than that and start to change, you may be suffering from a secondary infection. Both illnesses can leave you feeling pretty miserable, but these common complications of the cold and flu can make you feel even worse. Here's what you need to know about the most common cold and flu complications.

Ear infections are very common after a cold or the flu, especially a middle ear infection. Although adults do get them, they are much more common amongst children. They can be quite painful, but they're easily treatable with acetaminophen or ibuprofen.

Older children and adults are usually able to identify an ear infection based on pain alone. For younger children, identifying an ear infection is a bit more difficult. Be on the lookout for these signs:

• Pulling on the ear
• Crying more than usual
• Difficulty sleeping
• Drainage from the ear
• Problems with balance or hearing
• Unexplained fever

Sinus infections occur when mucus gets caught in the sinus cavities and they become infected. They can be very painful and affect people of all ages. They're very treatable with decongestants, pain relievers, and saline sprays and rinses. Symptoms of sinus infections include:

• Pain or pressure in the face, especially around the eyes and nose
• Congestion
• Headache
• Fever
• Weakness and fatigue
• Sore throat
• Cough that may become worse at night
• Bad breath
• Temporary loss of sense of smell

Because the flu may cause diarrhea and vomiting, dehydration may occur as your body has a hard time holding onto food and liquid.

Symptoms of dehydration include:

• Dry mouth
• Dark-colored urine
• Little or no urination
• Fatigue
• Headache

Do your best to prevent dehydration by keeping up with liquids such as water and herbal teas and eating soups and smoothies.

A nagging cough that lasts longer than two weeks may be bronchitis. It's likely caused by a virus, so it cannot be treated with antibiotics. See your healthcare provider, who will draw up a treatment plan.

Symptoms of bronchitis include:

• A cough that may start dry and painful, and become productive with yellow or green mucus
• Sore throat
• Chest pain
• Chest congestion
• Shortness of breath
• Wheezing
• Chills
• Body aches

A painful, productive cough may indicate pneumonia. This condition is marked by a lung infection in which the lungs' air sacs fill up with pus or another liquid that makes it difficult for oxygen to reach the bloodstream. It usually occurs after you've had an infection such as with a cold or flu—called a secondary infection—and may be a result of the flu virus alone or a co-infection of a virus and bacteria.

Pneumonia is a very serious illness that should be treated early, so contact your doctor immediately if you suspect any symptoms. 

Symptoms of pneumonia are:

• Frequent, painful and/or productive cough
• Extreme fatigue
• Chest pain
• Fever
• Chills
• Headaches
• Shortness of breath
• Bluish or grayish coloring around the mouth (cyanosis)
• Confusion or altered mental state

The following complications are much less common but rather serious. If the flu virus creeps into organs such as the brain or heart, it can cause widespread inflammation that may be life-threatening.

• Myocarditis: Inflammation of the heart
• Encephalitis: Inflammation of the brain
• Multi-organ failure: Including respiratory and kidney failure
• Sepsis: An infection in the bloodstream

According to the Centers for Disease Control and Prevention (CDC), those at highest risk for complications resulting from the flu include those with weaker immune systems, usually those within the following demographics:

• People over age 65
• Children under age 5
• Pregnant people
• Anyone with chronic medical conditions, such as asthma, diabetes, or heart disease 

A Word From Verywell

If you have recently had a cold or the flu and your symptoms have changed, worsened, or have not improved after two weeks, you should see your healthcare provider. This list includes only some of the most common complications, but there are many complications that occur from these illnesses, including a worsening of pre-existing conditions. A visit to your healthcare provider will help you identify what is causing your symptoms and get you on the right treatment plan for you.