ACEP COVID-19 Field Guide

Author: Mark Hauswald, MS, MD, FACEP, Emeritus Professor of Emergency Medicine, Past Associate Dean for Clinical Affairs and Patient Safety, Past Director of Global Health Projects, University of New Mexico Health Sciences Center

Prolonged symptoms after recovery from acute COVID-19 are common and multifactorial. Although not comprehensive, the CDC lists these potential long COVID symptoms:

General symptoms

• Tiredness or fatigue that interferes with daily life
• Symptoms that get worse after physical or mental effort (postexertional malaise)
• Fever

Respiratory and heart symptoms

• Difficulty breathing or shortness of breath
• Cough
• Chest pain
• Tachycardia or pounding heart (heart palpitations)

Neurologic symptoms

• Difficulty thinking or concentrating (brain fog)
• Headache
• Sleep problems
• Dizziness when standing up (light-headedness)
• Feelings of pins and needles
• Change in smell or taste
• Depression or anxiety
• Mood swings

Digestive symptoms

• Diarrhea
• Stomach pain

Other symptoms

• Joint or muscle pain
• Rash
• Changes in menstrual cycles

Known causes of prolonged post–COVID-19 symptoms include:

• Post-ICU syndrome, which is known to cause post-traumatic stress disorder, weakness, and mental status changes, including problems with thinking, judgment, and emotions;
• Myocarditis;
• Pulmonary injury; and
• Blood clots (clinical and probably subclinical).

Prolonged symptoms of COVID-19 are more common in patients with preexisting illnesses and after more severe illness, hospitalization, or ICU admission. The incidence of prolonged symptoms in post-ICU patients is 74% at 1 year. Prolonged symptoms are less common in vaccinated patients who subsequently develop COVID-19. Similar symptoms have been (rarely) reported from vaccination itself. The effect of second or subsequent COVID-19 infections on the likelihood of developing prolonged symptoms is unclear. Symptoms of the virus are milder in vaccinated or previously infected patients, so these patients are less likely to be diagnosed with acute COVID-19 in the first place. However, after a known reinfection, the incidence of prolonged symptoms is approximately doubled. Some evidence suggests that more recent virus variants are less likely to cause prolonged symptoms, but the data are complicated by increasing baseline immunity from the pandemic’s course. Women are about twice as likely to have prolonged symptoms as men (10.6% vs 5.4%). Children seem to be relatively protected from prolonged symptoms, although in one study 4% of them had at least one symptom at 12 weeks post infection.

The incidence of prolonged symptoms is difficult to determine because of problems with data collection and a lack of objective criteria. To complicate matters, similar prolonged symptoms occur following other viral illnesses. Functional disability after a hospitalization for COVID-19 is relatively high, with 60% of patients unable to perform all activities of daily living independently the first month and 40% unable to return to normal activities at 2 months. Long COVID is a recognized condition that can result in a disability under the Americans With Disabilities Act.

The cause of long COVID is not entirely known. The leading theories include damage from microemboli, mitochondrial dysfunction, and viral persistence.

When patients present to the emergency department with prolonged symptoms, physicians should consider known causes, such as cardiovascular disease (myocardial infarction, stroke, dysrhythmias, pericarditis, myocarditis, and heart failure are all more common post infection), pulmonary disease (acute or chronic), and acute emboli. The exact workup, as is typical in emergency medicine, depends on the time course, symptoms, and findings. No specific treatments exist for most patients with prolonged symptoms from COVID-19.

Fortunately, symptoms fade with time, and only 15% of patients diagnosed with long COVID have symptoms after 1 year.

Additional readings

• Clinical overview of long COVID. Centers for Disease Control and Prevention. Updated February 6, 2024.
• Long COVID basics. Centers for Disease Control and Prevention. Updated March 14, 2024.
• RECOVER: researching COVID to enhance recovery.
• Montoy JCC, Ford J, Yu H, et al; Innovative Support for Patients with SARS-CoV-2 Infections Registry (INSPIRE) Group. Prevalence of symptoms ≤12 months after acute illness, by COVID-19 testing status among adults — United States, December 2020-March 2023. MMWR. 2023 Aug 11;72(32):859-865. doi: 10.15585/mmwr.mm7232a2