When broken down by state, most of the country is experiencing elevated respiratory illness, including a few states with “very high” ratings that act as national hotspots, CDC data shows.

There’s no medication for norovirus. Instead, you’ll need to rehydrate as much as possible with water and other liquids. Seek help if you are dehydrated and notice you have a dry mouth and throat, aren’t urinating as much or feel dizzy when you’re standing up.

Most U.S. states are reporting high or very high flu-like activity, while COVID-19 rates remain lower than this time last year.

Influenza A, COVID-19 and norovirus (stomach flu) are on the rise, according to the Centers for Disease Control and Prevention. But there's a fourth "bug" the public should be aware of: respiratory syncytial virus. RSV causes cold-like symptoms and affects the breathing passages and lungs.

It’s sick season in Philly: the cold-weather months when cases of respiratory illnesses and the “stomach bug” norovirus rise. Some public health experts have called the combination of viruses circulating “the quad-demic” — referring to a wave of illness from the simultaneous spike in COVID-19,

Flu and COVID-19 case counts are high and rising in most parts of the United States, according to recent data by the Centers for Disease Control and Prevention (CDC). RSV case counts are also elevated in most states, especially in children.

The flu, norovirus, COVID and RSV are all at elevated levels — and officials at the CDC expect it to stay that way for weeks. NBC medical contributor Dr. Natalie Azar joins TODAY with tips for keeping you and your family healthy and what to know about vaccines.