Coronavirus Disease 2019 – Symptoms and Causes
Overview
COVID-19 is a disease caused by the SARS-CoV-2 virus. The virus primarily transmits through airborne droplets when infected people are in close proximity to others.
While many individuals experience no symptoms or only mild illness, COVID-19 poses significant risks for older adults and those with underlying health conditions, potentially leading to hospitalization or death.
Keeping current with COVID-19 vaccinations provides strong protection against severe illness and mortality. Additional preventive measures include ensuring proper indoor ventilation, maintaining physical distance from others, wearing masks in appropriate settings, and practicing good hygiene habits.
For those who do contract the virus, certain medications can help reduce the severity of infection. Most people recover completely from COVID-19, though some individuals experience long-term symptoms that persist for months after the initial infection.
Key prevention strategies:
- Staying up-to-date on vaccines
- Improving indoor air circulation
- Practicing physical distancing
- Wearing appropriate masks
- Maintaining good hand hygiene
Signs and Symptoms
COVID-19 symptoms typically appear 2 to 14 days after exposure to the virus. Many people experience different symptoms, and some may have very mild or no symptoms at all.
Common symptoms include:
- Dry cough
- Breathing difficulties
- Loss of taste or smell
- Severe tiredness
- Stomach issues (upset stomach, vomiting, diarrhea)
- Headaches and muscle pain
- Fever or chills
- Nasal congestion, runny nose, or sore throat
Some people test positive for COVID-19 but never develop symptoms. These individuals are called asymptomatic carriers. Others may initially have no symptoms but develop them later (presymptomatic).
Both groups can still spread the virus to others. For some patients, symptoms may worsen about 7 to 14 days after they first appear.
COVID-19 severity can range from mild toย critical.
| Severity | Description |
|---|---|
| Mild | Lung function remains normal; oxygen levels unaffected |
| Moderate | Lungs work properly, but infection has reached deep into lungs |
| Severe | Lung function compromised; requires oxygen and hospital care |
| Critical | Respiratory system failure with damage to multiple body systems |
Most people experience mild to moderate symptoms. However, serious complications can occur, especially in older adults and people with existing health conditions.
When to Get Medical Help
Seek emergency care immediately if you experience:
- Difficulty breathing
- Bluish or gray coloring in lips, skin, or nail beds
- New confusion or disorientation
- Inability to stay awake or difficulty waking
- Persistent chest pain or pressure
If you test positive for COVID-19 or have been exposed to someone with it, contact a healthcare provider. People at high risk for severe illness might receive medications to limit viral spread in the body.
Causes
SARS-CoV-2 is the virus that leads to COVID-19. This virus primarily spreads through respiratory droplets from one person to another.
When infected individuals breathe, talk, cough, or sneeze, they release virus-containing particles into the air. These particles can spread in several ways:
- Direct contact with respiratory droplets that land on someone’s face
- Breathing in airborne viral particles, especially in poorly ventilated spaces
- Touching contaminated surfaces and then touching the face
Individuals can contract COVID-19 repeatedly. This happens for several reasons:
- Immunity may decrease over time after infection
- Exposure to large amounts of the virus can overcome immune defenses
- Viral mutations can help the virus evade previous immunity
The virus continuously changes as it spreads. These genetic changes, called mutations, sometimes allow the virus to bypass protection from prior infections or vaccines.
Some animals can also become infected with SARS-CoV-2. Pets like cats, dogs, hamsters, and ferrets have contracted the virus and shown symptoms. However, pet-to-human transmission is uncommon.
Infection risk increases in crowded indoor settings with poor ventilation. In these environments, viral particles can accumulate in the air and remain infectious for longer periods. This explains why outbreaks often occur in settings like:
| High-Risk Settings | Reason |
|---|---|
| Indoor gatherings | Limited air circulation |
| Crowded spaces | Close proximity to others |
| Poorly ventilated areas | Particles remain airborne longer |
What Increases Your Risk
Several health conditions and demographic factors can increase a person’s risk of developing serious complications from COVID-19.
Adults over 65 and babies under 6 months are at a higher risk compared to other age groups. Both these groups show the highest rates of hospitalization when infected.
People who have not received COVID-19 vaccines are at a higher risk of severe illness. While serious cases can affect anyone, including those without pre-existing conditions, certain medical conditions significantly increase the risk.
Blood Disorders
- Sickle cell disease
- Thalassemia
Heart and Vascular Issues
- Serious heart conditions
- Possibly high blood pressure
Chronic Conditions
- Kidney disease
- Liver disease
- Lung disease
Neurological Conditions
- Dementia
- Alzheimer’s disease
- History of stroke
- Other brain and nervous system disorders
Lifestyle Factors
- Current smoking
- Overweight or obesity
People with weakened immune systems face particularly high risks. This includes organ or bone marrow transplant recipients, individuals on immunosuppressive medications, and those living with HIV.
Cancer patients and those with a history of cancer need to take extra precautions. Both type 1 and type 2 diabetes also increase the likelihood of severe COVID-19 complications.
Pregnant women should be especially careful, as pregnancy can make COVID-19 illness more dangerous.
The risk increases substantially when someone has multiple health conditions at once. An older adult with both diabetes and heart disease has a much higher risk than someone with only one of those conditions.
Social and environmental factors also play important roles in determining risk. People living in group settings or those with limited access to health care may experience worse outcomes.
Health Problems After COVID-19
Long COVID Syndrome
Long COVID is when symptoms last for months after a COVID-19 infection, or when new health issues develop. This condition goes by several names including post-COVID syndrome, long haul COVID, and PASC (post-acute sequelae of SARS-CoV-2).
COVID-19 can lead to a myriad of persistent complications. Some people experience:
- Breathing difficulties
- Loss of taste or smell
- Skin problems like rashes and sores
- Worsening of existing health conditions
Long COVID can affect anyone, regardless of whether they experienced only mild symptoms during their initial infection. Research shows that getting vaccinated may help reduce the risk of developing this condition.
More serious COVID-19 cases may lead to several dangerous complications:
| Complication | Description |
|---|---|
| Respiratory distress | Body organs don’t get enough oxygen |
| Shock | Caused by infection or heart problems |
| Immune system overreaction | Excessive inflammatory response |
| Blood clots | Can form in various parts of the body |
| Kidney damage | Can affect kidney function |
Scientists continue to study the long-term effects of COVID-19. COVID-19 has only been studied since 2019, so our understanding of it is still evolving, unlike more established infections like influenza and polio that can cause lasting issues.
Ways to Protect Yourself
Travel connects people from different areas where illness rates may vary. When you travel, you face unique health challenges that require careful planning.
Here are some key ways to protect yourself during trips:
Mask Wearing Considerations:
- Masks help reduce the spread of COVID-19 and other respiratory illnesses
- They are most effective in poorly ventilated spaces and crowded areas
- Masks are particularly important when visiting locations with high infection rates
- They are also recommended for those at higher risk of serious illness
Before Your Trip:
- Check current COVID-19 levels at your destination
- Ensure your vaccines are up to date
- Pack masks, hand sanitizer, and disinfecting wipes
- Also, consider testing before departure if visiting vulnerable individuals
During Travel:
- Wash hands frequently with soap and water for 20 seconds
- Use hand sanitizer with at least 60% alcohol when soap isn’t available
- Avoid touching your face, especially after touching public surfaces
- Maintain distance from others when possible, particularly in crowded terminals
Air Travel Tips:
- Wear a well-fitting mask in crowded airports and potentially on flights
- Choose window seats when possible (less exposure to passing people)
- Turn on air vents above your seat to improve air circulation
- Wipe down tray tables, armrests, and entertainment screens
Transportation options vary in their risk levels. Driving in your own vehicle typically poses a lower transmission risk than shared transportation. Meanwhile, trains and buses present moderate risk depending on crowding and ventilation.
Cruise ships require special consideration due to their enclosed environments and communal activities.
Accommodation Safety:
- Consider contactless check-in when available
- Open windows to improve ventilation when possible
- Limit time in common areas like lobbies and elevators
- Wipe down high-touch surfaces in your room
Testing Considerations:
- Test 5 days after potential exposure, or before visiting vulnerable people
- Carry self-tests with you during your travels for convenience
- Know how to access testing at your destination if symptoms develop
- Also, follow local guidelines for isolation if you test positive while traveling
Pay special attention to your health while traveling. Monitor for symptoms like fever, cough, or fatigue. If you develop symptoms, isolate yourself from others and test promptly. Having a plan for accessing healthcare at your destination is essential.
When returning home, be mindful of protecting others. Consider getting tested after your trip, particularly if you visited areas with high COVID-19 rates or plan to be around vulnerable people.
Traveling internationally brings forth unique challenges. Research entry requirements for your destination, as some countries may have specific testing, vaccination, or quarantine rules.
Special considerations for high-risk travelers:
- Consult your healthcare provider before traveling
- Carry all needed medications, plus extras
- Know how to contact your doctor while you are away
- Consider medical evacuation insurance for international travel
By taking these precautions, you can significantly reduce your risk while enjoying your travels. Careful planning, consistent preventive measures, and staying informed are your best tools for healthier trips.
