<unk> <unk>  are variable, ranging from mild<unk>  to critical and possibly fatal illness. Common<unk>  include coughing, fever, loss of smell (anosmia) and taste (ageusia), with less common ones including headaches, nasal congestion and runny nose, muscle pain, sore throat, diarrhea, eye irritation, and toes swelling or turning purple, and in moderate to severe cases breathing difficulties. People with the COVID-19 infection may have different<unk> , and their<unk>  may change over time. Three common clusters of<unk>  have been identified: one respiratory<unk> cluster with cough, sputum, shortness of breath, and fever; a musculoskeletal<unk> cluster with muscle and joint pain, headache, and fatigue; a cluster of digestive<unk>  with abdominal pain, vomiting, and diarrhea. In people without prior ear, nose, and throat disorders, loss of taste combined with loss of smell is associated with COVID-19 and is reported in as many as 88% of<unk> tic cases. Of people who show<unk> , 81% develop only mild to moderate<unk>  (up to mild pneumonia), while 14% develop severe<unk>  (dyspnea, hypoxia, or more than 50% lung involvement on imaging) which requiring hospitalization and 5% of patients suffer critical<unk>  (respiratory failure, septic shock, or multiorgan dysfunction) requiring ICU admission. At least a third of the people who are infected with the virus do not develop noticeable<unk>  at any point in time. These asymptomatic carriers tend not to get tested and can still spread the disease. Other infected people will develop<unk>  later, called "pre-symptomatic", or have very mild<unk>  and can also spread the virus. As is common with infections, there is a delay between the moment a person first becomes infected and the appearance of the first<unk> . The median delay for COVID-19 is four to five days possibly being infectious on 1-4 of those days. Most<unk> tic people experience<unk>  within two to seven days after exposure, and almost all will experience at least one<unk> within 12 days. Most people recover from the acute phase of the disease. However, some people – over half of a cohort of home-isolated young adults – continue to experience a range of effects, such as fatigue, for months even after recovery, a condition called long COVID; long-term damage to organs has been observed. Multi-year studies are underway to further investigate the potential long-term effects of the disease.
Symptoms of COVID-19
Cutaneous manifestations of COVID-19
Living with COVID-19
Long COVID
Rabies in animals
Far East scarlet-like fever
Transmission of COVID-19
Lyme disease microbiology