Doctors say some people are now reporting night sweats, a symptom also associated with sleep disorders, some cancers and the flu.
According to Mayo Clinic, night sweats are "repeated episodes of extreme perspiration that may soak your nightclothes or bedding and are related to an underlying medical condition or illness."
Appearing on ITV's "Lorraine," Dr. Amir Khan of the U.K.'s National Health Service called on the agency to update its symptoms list – including night sweats.
Typical COVID-19 symptoms, according to the Centers for Disease Control and Prevention (CDC), include fever or chills, cough, shortness of breath or trouble breathing, fatigue, muscle or body aches, headache, sore throat, congestion or runny nose, diarrhea, nausea or vomiting and new loss of taste or smell.
People can best protect themselves from the omicron variant by staying "up to date" on their COVID-19 vaccines, as well as wearing a well-fitting mask indoors in public setting, social distancing and washing hands with soap and water.
While there are still many unknowns about the variant, CDC data shows omicron accounts for approximately 98% of new COVID-19 cases.
According to the Johns Hopkins Coronavirus Resource Center, the U.S. has seen 776,455 new cases in the last day and 1,875 deaths.
America has reported more than 64 million confirmed cases and over 846,400 deaths since the beginning of the pandemic.