Common Cold and Flu Complications

While both the common cold and flu can leave you feeling pretty miserable, the complications of these illnesses can sometimes make you feel even worse or pose more serious concerns. From dehydration to secondary infections (e.g., ear infections or pneumonia), it's important to pay attention to what symptoms are occurring with a cold or the flu—especially noticing if they're lasting longer than seven to 10 days or are worsening.

Some people are at greater risk of developing more serious complications from common illnesses, which is why it's so important to focus on prevention (like getting a flu shot) and proper care if you do get sick.

Dehydration

Because the flu may cause diarrhea and vomiting and common colds may decrease your appetite, dehydration may occur as your body has a hard time holding onto food and liquid or a lack of interest in eating or drinking in the first place.

Symptoms of dehydration include:

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

Do your best to prevent dehydration by consuming liquids such as water, herbal teas, soups, and smoothies.

Ear Infections

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 in children.

Ear infections can be quite painful, but they're easily treatable with antibiotics in most cases. Taking acetaminophen or ibuprofen will not cure them, but can relieve related pain. (Note: Only give acetaminophen to children younger than 6 months.)

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
• Tilting head from one side
• Crying more than usual
• Difficulty sleeping
• Drainage from the ear
• Problems with balance or hearing
• Unexplained fever

Sinus Infections

Sinus infections occur when mucus gets caught in the sinus cavities and they become infected. These infections can be very painful and affect people of all ages.

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
• Loss of sense of smell

Sinus infections are very treatable with decongestants, pain relievers, and saline sprays and rinses.

Bronchitis

A nagging cough that lasts longer than two weeks may be bronchitis. It's likely caused by a virus, so it can't be treated with antibiotics.

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

If you notice any of the above, see your healthcare provider, who can evaluate you and recommend a treatment plan.

Pneumonia

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.

Pneumonia is typically a secondary infection—one that occurs after you've had an infection such a cold or the flu. It may be viral or a co-infection of a virus and bacteria.

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

Rare Complications

The following complications are much less common, though they are worthy of attention because they are 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

People at Greatest Risk

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 and especially those under age 2
• Pregnant people
• Anyone with chronic medical conditions, such as asthma, diabetes, or heart disease
• Those undergoing chemotherapy, who have had an organ transplant, have HIV, or have another medical circumstance causing them to be immunocompromised individuals

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 complications—there are many more 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.