COMPLICATIONS OF FLU

Sinus, throat and ear infections are examples of moderate complications from flu, while pneumonia is a serious complication that can result from either influenza virus infection alone or from co-infection of flu virus and bacteria. Other possible serious complications triggered by flu can include inflammation of the heart (myocarditis), brain (encephalitis) or muscle (myositis, rhabdomyolysis) tissues, and multi-organ failure (for example, respiratory and kidney failure).

Flu virus infection of the respiratory tract can trigger an extreme inflammatory response in the body and can lead to sepsis, the body’s life-threatening response to infection. Flu also can make chronic medical problems worse. For example, people with asthma may experience asthma attacks while they have flu, and people with chronic heart disease may experience a worsening of this condition triggered by flu.

People at high risk of developing flu-related complications

Children younger than 5, but especially children younger than 2 years old
Adults 65 years of age and older
Pregnant women and women up to two weeks postpartum
Residents of nursing homes and other long-term care facilities

People who have medical conditions including:

Asthma
Neurological and neurodevelopmental conditions (including disorders of the brain, spinal cord, peripheral nerve, and muscle such as cerebral palsy, epilepsy, stroke, intellectual disability, moderate to severe developmental delay, muscular dystrophy, or spinal cord injury)
Chronic lung disease (such as chronic obstructive pulmonary disease [COPD] and cystic fibrosis)
Heart disease (such as congenital heart disease, congestive heart failure and coronary artery disease)
Blood disorders (such as sickle cell disease)
Endocrine disorders (such as diabetes)
Kidney disorders
Liver disorders
Metabolic disorders (such as inherited metabolic disorders and mitochondrial disorders)
Weakened immune system due to disease or medication (such as people with HIV or AIDS, or cancer, or those on chronic steroids)
People younger than 19 years of age who are receiving long-term aspirin therapy
People with extreme obesity (body mass index [BMI] of 40 or more)

What are the emergency warning signs of flu sickness?

In children

Fast breathing or trouble breathing
Bluish skin color
Not drinking enough fluids
Not waking up or not interacting
Being so irritable that the child does not want to be held
Flu-like symptoms improve but then return with fever and worse cough
Fever with a rash

In adults

Difficulty breathing or shortness of breath
Pain or pressure in the chest or abdomen
Sudden dizziness
Confusion
Severe or persistent vomiting
Flu-like symptoms that improve but then return with fever and worse cough

In addition to the signs above, get medical help right away for any infant who has any of these signs:

Being unable to eat
Has trouble breathing
Has no tears when crying
Significantly fewer wet diapers than normal