With cases of the delta coronavirus variant sparking surges across the country, what should you know about your symptoms and when should you get tested?
According to the Centers for Disease Control and Prevention, the common cold, allergies and coronavirus overlap in some symptoms, like the potential for a cough, shortness of breath or breathing difficulties, fatigue, headaches, a sore throat and congestion.
Symptoms more associated with coronavirus include fever, muscle and body aches, loss of taste or smell, nausea or vomiting and diarrhea.
Chicago health officials say it can be difficult to tell whether symptoms are related to seasonal allergies, a common cold or the coronavirus, but getting tested is one way to find out. That includes people who have been vaccinated for coronavirus, experts say.
"Anybody with symptoms, that's the most important group of people to test," Dr. Isaac Ghinai, an epidemic intelligence service officer with the Chicago Department of Public Health, said earlier in the summer. "If you have any symptoms of possible COVID, whether it's even just a mild cough, you know, any of those kinds of mild symptoms, we would still recommend COVID testing."
For some people, coronavirus causes mild or moderate symptoms that clear up in a couple weeks. For others, it may cause no symptoms at all. For some, the virus can cause more severe illness, including pneumonia and death.
Even those who receive the coronavirus vaccine can also still contract the virus and may experience symptoms. Though rare, breakthrough cases have been reported in both Chicago and Illinois.
Most vaccinated people either have no symptoms or exhibit very mild symptoms, according to health officials, and the virus rarely results in hospitalization or death for those individuals.
Some residents who contracted breakthrough infections have said they experienced minor symptoms.
"I started feeling congested, similar to what I would feel like if I had seasonal allergies," Robert Flinn told NBC Chicago after he contracted coronavirus while fully vaccinated this summer.
But eventually, he said his symptoms grew to developing a fever, fatigue and a headache.
"It's like a really nasty cold," another Chicagoan, Robert Coy, said after contracting the virus following a trip to Provincetown, Massachusetts in July. "You'll get a bit of a cough, maybe, and you just feel tired and it's not fun."
Coronavirus and the common cold share many symptoms.
According to the Mayo Clinic, diarrhea and nausea or vomiting are the only symptoms associated with coronavirus that don't overlap with the common cold.
The hospital also notes that while COVID-19 symptoms generally appear two to 14 days after exposure to SARS-CoV-2, symptoms of a common cold usually appear one to three days after exposure to a cold-causing virus.
Last fall, Illinois' top public health official warned that people should take notice of any potential coronavirus symptoms as they could be confused with seasonal allergies.
"I keep hearing from my contact tracers at the local health departments that they're hearing the same story over and over: 'I had no idea that I was positive. The symptoms I had I thought were allergy symptoms. I never would have thought it was COVID,'" Illinois Department of Public Health Director Dr. Ngozi Ezike said at the time.
Seasonal allergies can sometimes bring with them a cough and runny nose - both of which can be associated with some coronavirus cases, or even the common cold - but they also bring itchy or watery eyes and sneezing, symptoms that are uncommon in coronavirus patients.
Allergies can occasionally be met with a loss of taste or smell.
The CDC reports that pollen exposure can trigger allergic reactions, such as symptoms of hay fever.
"Hay fever, also known as allergic rhinitis, occurs when allergens like pollen enter your body and your immune system mistakenly identifies them as a threat," the CDC states. "If you have allergic rhinitis, your body then responds to the allergen by releasing chemicals that can cause symptoms in the nose."
Such symptoms - which include sneezing, runny nose and congestion - affect as many as 60 million people per year in the United States, the CDC reports.
Pollen exposure can also trigger symptoms of what's known as allergic conjunctivitis, or the "inflammation of the lining of the eye due to exposure to allergens like those in pollen."
"Allergic conjunctivitis is found in up to 30% of the general population and as many as 7 out of 10 of patients with allergic rhinitis," the CDC reports, adding that symptoms from allergic conjunctivitis include red, watery, or itchy eyes.
Health officials say you shouldn't ignore your symptoms and should pay close attention.
"Please don't overlook those allergy-like symptoms," Ezike said. "COVID can look like so many things."