DEFINITION
COVID-19 (Coronavirus Disease 2019) is an infectious disease caused by the SARS-CoV-2 virus. This respiratory illness can affect multiple systems in the body and ranges from asymptomatic or mild cases to severe illness requiring hospitalization. The virus primarily spreads through respiratory droplets and aerosols when an infected person breathes, talks, coughs, or sneezes.

EPIDEMIOLOGY AND CAUSES
COVID-19 was first identified in Wuhan, China, in December 2019 and rapidly spread worldwide, leading to a global pandemic declaration by the World Health Organization in March 2020. The virus has continued to evolve, producing multiple variants with different characteristics. The disease affects people of all ages, though certain groups face higher risks of severe illness.

Risk factors for severe COVID-19 include advanced age, obesity, diabetes, heart conditions, chronic respiratory diseases, immunocompromised states, and certain other underlying medical conditions. While some populations face higher risks, the virus can cause serious illness in previously healthy individuals of any age.

Transmission primarily occurs through close contact with infected individuals, particularly in poorly ventilated indoor spaces. The virus can also spread through contact with contaminated surfaces, though this is less common. Asymptomatic and pre-symptomatic transmission has been documented, making containment particularly challenging.

HOW COMMON IS COVID-19
COVID-19 has affected hundreds of millions of people globally. The exact number of cases is difficult to determine due to varying testing capabilities across regions and the presence of asymptomatic cases. The disease has led to millions of deaths worldwide, though mortality rates have varied significantly across different populations and time periods, influenced by factors such as vaccination status, variant characteristics, and healthcare system capacity.

PRESENTATION
COVID-19 symptoms typically appear 2-14 days after exposure to the virus. Common symptoms include fever or chills, cough, shortness of breath, fatigue, muscle or body aches, headache, loss of taste or smell, sore throat, congestion or runny nose, nausea or vomiting, and diarrhea. The severity and combination of symptoms can vary greatly among individuals, with some experiencing no symptoms at all.

Long COVID, also known as post-acute COVID-19 syndrome, can occur in some individuals who experience persistent symptoms or develop new health issues after the acute phase of infection. These symptoms can last for weeks, months, or longer and may include fatigue, brain fog, shortness of breath, joint pain, and other conditions.

SEVERE COVID-19
Severe COVID-19 can develop rapidly and requires immediate medical attention. Warning signs include severe difficulty breathing, persistent chest pain or pressure, confusion, inability to stay awake or wake up, and bluish lips or face. These symptoms indicate potential complications such as acute respiratory distress syndrome (ARDS), blood clots, organ failure, or other life-threatening conditions.

WHEN TO SEEK TREATMENT
Seek emergency medical care immediately if you experience severe difficulty breathing, persistent chest pain or pressure, new confusion, inability to wake or stay awake, or bluish lips or face. Contact your healthcare provider if you develop any COVID-19 symptoms or have been exposed to someone with confirmed COVID-19. Testing is recommended to confirm infection and guide isolation decisions.

WORKUP
Diagnosis typically involves viral testing through PCR tests or rapid antigen tests. Additional workup may include chest X-rays, CT scans, blood oxygen level monitoring, and blood tests to assess organ function and inflammatory markers. The extent of testing depends on symptom severity and risk factors. Home testing has become widely available, though positive results should be reported to healthcare providers.

TREATMENT
Treatment approaches vary based on illness severity. Mild cases can often be managed at home with rest, hydration, and over-the-counter medications for symptom relief. Antiviral medications may be prescribed for individuals at high risk of severe illness. Severe cases may require hospitalization, oxygen therapy, or intensive care. Prevention through vaccination, masking in high-risk situations, and maintaining good ventilation remains crucial in managing disease spread.

POPULAR MISCONCEPTIONS
• "COVID-19 is just like the flu." While both are respiratory illnesses, COVID-19 can be more severe and has unique characteristics, including the potential for long-term complications and higher transmission rates in certain variants.

• "Young, healthy people don't need to worry about COVID-19." While risk increases with age and certain conditions, young and healthy individuals can develop severe illness or long COVID, and can transmit the virus to more vulnerable populations.

• "Once you've had COVID-19, you can't get it again." Reinfection is possible, particularly with new variants. While prior infection provides some immunity, its duration and effectiveness against new variants vary, making continued precautions and vaccination important.