infectious disease

The U.S. is experiencing the highest number of flu hospitalizations in a decade, and there’s no sign that the virus is going to peak or go away in the coming weeks. With the busy holiday travel season approaching and a comparatively low percentage of adults vaccinated for the flu, that leaves millions at potential risk for severe complications.

While most people who get flu will recover in a few days, some can develop life-threatening complications. There have been at least 7,300 deaths from flu, including 21 children, since October, according to the latest data from the Centers for Disease Control and Prevention. 

Approximately 120,000 people have been hospitalized for the flu in the last couple of months, the CDC reported. Nine out of 10 adults hospitalized with flu had at least one underlying medical condition.

People most at risk of serious illness from the flu include children under age 5, people over age 65, immunocompromised people and people who are pregnant.

People with complications of the flu end up in the hospital most often because the virus develops into pneumonia, said Dr. Peter Chin-Hong, professor of medicine and an infectious disease physician at the University of California, San Francisco. 

Bacterial pneumonia may develop when the flu virus spreads to the lower respiratory tract, leading to breathing difficulties that may require supplemental oxygen.

Warning signs of pneumonia 

While many of the symptoms of influenza, such as fever and body aches, overlap with pneumonia, there are some clues that may indicate a more serious lung infection may be brewing. 

A cough with yellow or green sputum, increasing fever, and pain in the chest when taking a deep breath or coughing are warning signs of pneumonia.

Some patients with pneumonia may also go on to develop sepsis, a complication that could lead