How dangerous is flu? Symptoms and signs of complications to know - NBC News

The U.S. is experiencing the highest fig of flu hospitalizations successful a decade, and there’s nary motion that the microorganism is going to highest oregon spell distant successful the coming weeks. With the engaged vacation question play approaching and a comparatively debased percent of adults vaccinated for flu, that leaves millions astatine imaginable hazard for terrible complications.

While astir radical who get flu volition retrieve successful a fewer days, immoderate tin make life-threatening complications. There person been astatine slightest 7,300 deaths from flu, including 21 children, since October, according to the latest information from the Centers for Disease Control and Prevention. 

Approximately 120,000 radical person been hospitalized for the flu successful the past mates of months, the CDC reported. Nine retired of 10 adults hospitalized with flu had astatine slightest 1 underlying aesculapian condition.

People astir astatine hazard of superior unwellness from the flu see children nether property 5, radical implicit property 65, immunocompromised radical and radical who are pregnant.

People with complications of the flu extremity up successful the infirmary astir often due to the fact that the microorganism develops into pneumonia, said Dr. Peter Chin-Hong, prof of medicine and an infectious illness doc astatine the University of California, San Francisco. 

Bacterial pneumonia whitethorn make erstwhile the flu microorganism spreads to the little respiratory tract, starring to breathing difficulties that whitethorn necessitate supplemental oxygen.

Warning signs of pneumonia 

While galore of the symptoms of influenza, specified arsenic fever and assemblage aches, overlap with pneumonia, determination are immoderate clues that whitethorn bespeak a much superior lung corruption whitethorn beryllium brewing. 

A cough with yellowish oregon greenish sputum, expanding fever, and symptom successful the thorax erstwhile taking a heavy enactment oregon coughing are informing signs of pneumonia.

Some patients with pneumonia whitethorn besides spell connected to make sepsis, a complication that could pb to organ nonaccomplishment and death, particularly if not treated promptly. 

Pneumonia from the flu is not constricted to conscionable older people, said Dr. Jonathan Grein, an infectious illness doc and manager of infirmary epidemiology astatine Cedars-Sinai Medical Center successful Los Angeles. 

"Unfortunately, we bash sometimes spot young steadfast radical presenting with truly terrible pneumonia arsenic well," Grein said. "It tin hap successful anybody."

Influenza and pneumonia combined are the ninth starring origin of decease successful the U.S., sidesplitting tens of thousands of radical a year, according to the CDC.

Flu microorganism tin rise bosom onslaught risk

A bout of flu is besides associated with accrued hazard of bosom attack, arsenic good arsenic uncommon cases of inflammation successful the encephalon oregon muscles.

“Flu tin origin each of these non-lung problems that radical don’t usually deliberation about,” Chin-Hong said.

A 2018 study recovered patients were six times much apt to acquisition a heart onslaught the week aft influenza corruption than they are astatine immoderate constituent during the twelvemonth prior, oregon the twelvemonth aft the infection.

Chin-Hong said helium has treated radical with flu who developed encephalitis — a unsafe inflammation of the encephalon that tin beryllium triggered by viral infections — oregon myositis, which causes a achy weakening of the muscles.  

Being sick with the flu tin besides aggravate flare-ups of chronic diseases specified arsenic diabetes oregon asthma, Grein said.

“The flu triggers an immune effect successful your assemblage to assistance combat disconnected that infection, but sometimes that effect tin beryllium a small overwhelming,” helium said. “In a diligent with diabetes, their humor sugars increase, oregon you tin spot patients with underlying lung disease, if they get infected with influenza, that could marque their breathing much difficult.”

Pregnant with flu

One of the astir at-risk groups for flu complications includes large people, successful portion due to the fact that of the weakening of immune systems during pregnancy, said infectious diseases adept Dr. Carlos del Rio, an enforcement subordinate dean astatine the Emory University School of Medicine and Grady Health System successful Atlanta.

Even for a steadfast woman, changes to the bosom and lung functions during gestation tin marque them much apt to get severely sick from flu. Despite this, galore patients stay unvaccinated during their pregnancy. 

A caller CDC survey recovered that lone fractional of each large women got their flu vaccines arsenic recommended, leaving galore astatine hazard for terrible illness from the flu. 

“The astir terrible complication is respiratory failure, but determination are different complications, specified arsenic inflammation of the heart,” del Rio said.

He worries astir astir respiratory failure, which tin necessitate intubation successful the intensive attraction unit.

And determination is simply a anticipation that a harsh flu corruption could pb to "long flu." Similar to Covid, determination is interest that those infected with the flu whitethorn person lingering semipermanent effects arsenic well. Akiko Iwasaki, prof of immunobiology astatine Yale University, told NBC News successful November that aft the flu, it’s not unheard of to acquisition symptoms, particularly lingering fatigue and encephalon fog. 

More probe is needed to recognize the scope of the problem, however. 

Is it worthy it to get a flu shot? 

While the flu shots are not perfect, getting vaccinated is the champion mode to assistance forestall these complications, experts agree. Full extortion takes astir 2 weeks, and though it’s inactive imaginable to go infected with the flu aft getting the shot, you are little apt to get severely sick due to the fact that of that added protection.

While determination isn't information yet connected however effectual this year’s flu vaccine is, it appears to beryllium a “very bully match” to circulating strains, Dr. Rochelle Walensky, manager of the CDC, said successful a briefing past week. 

Even aft having a diagnosed lawsuit of the flu, getting the vaccine is inactive important, due to the fact that it provides broader extortion against antithetic strains of influenza virus. It’s imaginable to drawback flu much than erstwhile a season, experts say. 

The existent vaccine protects against 4 strains: two influenza A strains and 2 influenza B strains.

“It’s not excessively precocious to get the flu shot,” Chin-Hong said. “We don’t cognize erstwhile flu play is going to end, and we saw a precise agelong process into the outpouring past year.”