Right now, several infections are circulating at the same time across the United States, which is why it feels like everyone around you is sick. The main culprits include flu, COVID-19, common cold viruses, RSV, norovirus, and a major surge in whooping cough. Here’s what’s actually going around and how to tell what you might have.
Flu and COVID Are Still in the Mix
Influenza remains one of the most common reasons people are feeling miserable. The 2024-2025 flu season followed a familiar pattern, with activity climbing through the winter months. This season’s flu vaccine offered roughly 42% to 56% protection against outpatient illness in adults, depending on the study, and around 59% effectiveness in children and teens. That means vaccination cut the odds of a doctor visit roughly in half, though plenty of vaccinated people still caught milder cases.
COVID-19 continues to circulate alongside the flu, though it no longer dominates hospital wards the way it did in earlier years. The virus still causes waves of illness, and wastewater surveillance systems track its levels in communities nationwide. Symptoms overlap heavily with the flu: fever, cough, fatigue, body aches, and sore throat. One distinguishing feature of COVID is a sudden loss of taste or smell early in illness, often without much nasal congestion. Diarrhea and nausea also show up more frequently with COVID than with a typical cold.
Cold Viruses Peak Twice a Year
Rhinoviruses and enteroviruses, the most common causes of the plain old cold, don’t follow the same winter-only schedule as the flu. CDC surveillance data from the current season show two distinct peaks: one in the fall, when 30.4% of tests came back positive in late September 2024, and a second wave in the spring, reaching 22.3% positivity in May 2025. Even during the lowest points of the year, at least 10% of tests were positive, meaning cold viruses never fully disappear.
Seasonal coronaviruses (not SARS-CoV-2, but its milder relatives) peaked in late February 2025 at 8.3% positivity. These cause cold-like symptoms and tend to hit hardest in midwinter. RSV, which is especially dangerous for young children and older adults, followed its pre-pandemic timing this season, with elevated activity from October through April.
Whooping Cough Made a Major Comeback
One of the biggest stories of 2024 was the return of pertussis, commonly known as whooping cough. The U.S. recorded over 35,400 cases in 2024, a rate of about 10.6 per 100,000 people. That’s a dramatic jump compared to recent years, when cases had been historically low partly due to pandemic-era social distancing and masking.
The age group hit hardest was 11 to 19 year olds, who accounted for nearly 43% of all cases. School-age children between 7 and 10 made up another 14%. Infants under 6 months old represented a smaller share of total cases (4.4%) but faced the most serious consequences: one in three was hospitalized. Adults over 20 also had a notable hospitalization rate of about 10%, likely because the illness can linger for weeks with violent coughing fits that crack ribs or cause vomiting.
Whooping cough starts out looking like a mild cold for the first week or two, with a runny nose and low-grade fever. The telltale sign comes later: intense coughing spells that can last a minute or more, sometimes ending with a high-pitched “whoop” as the person gasps for air. In adults and teens the whoop isn’t always present, so it often gets mistaken for a stubborn cough that just won’t quit.
Norovirus and Stomach Bugs
It’s not all respiratory. Norovirus, the leading cause of vomiting and diarrhea outbreaks, follows a reliable seasonal curve that peaks between December and March. If you’ve had a sudden onset of nausea, vomiting, watery diarrhea, and stomach cramps that hits like a freight train and lasts one to three days, norovirus is the most likely explanation during those months.
Norovirus spreads incredibly easily. A tiny amount of virus is enough to make someone sick, and it can survive on surfaces for days. Outbreaks tear through households, schools, cruise ships, and restaurants. Alcohol-based hand sanitizers are less effective against it than plain soap and water, so thorough handwashing is your best defense.
How to Tell What You Have
With so many things circulating at once, figuring out what hit you can be tricky. A few patterns help narrow it down:
- Fever plus body aches plus sudden onset: This combination points toward the flu or COVID rather than a cold. Colds tend to build gradually over a day or two, while flu often arrives all at once.
- Loss of taste or smell without much congestion: Still a hallmark of COVID, especially early in the illness.
- Itchy eyes, nose, or roof of the mouth: Almost certainly allergies, not an infection. Allergies also never cause fever or muscle aches.
- Violent coughing that worsens over weeks: Consider whooping cough, particularly if the cough comes in fits and you feel fine between episodes.
- Vomiting and diarrhea with little respiratory involvement: Likely norovirus or another stomach bug, especially if it comes on fast and resolves within a few days.
Home tests for COVID and flu are widely available at pharmacies and can help you sort things out within minutes. If your cough has lasted more than two weeks and is getting worse rather than better, a healthcare provider can test for pertussis with a nasal swab.
Why It Feels Like Everyone Is Sick at Once
The layering effect is real. Cold viruses circulate nearly year-round, flu and RSV dominate the winter, norovirus peaks in late winter, and whooping cough surged on top of all of it in 2024. Add in COVID, which no longer follows a strict seasonal pattern, and you get stretches where multiple waves overlap. Wastewater surveillance now tracks many of these pathogens simultaneously, giving public health officials early warning when levels rise in a community, sometimes before hospitals see the increase in patients.
The post-pandemic years have also seen shifting immune patterns. Many people, especially young children, missed typical exposures during lockdowns and are encountering some viruses for the first time later than usual. This “immunity gap” has contributed to larger-than-expected surges in RSV and whooping cough. Over time, as exposure patterns normalize, these swings are expected to level out.