COVID-19 symptoms can sometimes persist for months. The virus can damage the lungs, heart and brain, which increases the risk of long-term health problems. Clinical evidence is evolving on the subacute and long-term effects of COVID-19, which can affect multiple organ systems. The residual effects of SARS-CoV-2 infection include fatigue, shortness of breath, chest pain, cognitive disturbances, joint pain and decline in quality of life. Cellular damage, a robust immune response with inflammatory cytokine production, and a pro-coagulant state induced by Covid-19 infection may contribute to these complications.
Most people who have COVID-19 recover completely within a few weeks. But some people — even those who had mild disease — continue to experience symptoms after their initial recovery. These health issues are usually called post-COVID-19 conditions. They’re generally considered to be effects of COVID-19 that persist for more than four weeks after a person has been diagnosed with the COVID-19 virus. Based on recent information, it is further divided into two categories: (1) subacute or ongoing symptomatic COVID-19, which includes symptoms and abnormalities present from 4–12 weeks beyond acute COVID-19; and (2) chronic or post-COVID-19 syndrome, which includes symptoms and abnormalities persisting or present beyond 12 weeks of the onset of acute COVID-19 and not attributable to alternative diagnoses.
Elderly people and people with other medical conditions are the most likely to experience post COVID-19 symptoms. However, young, otherwise healthy people can feel post covid symptoms for weeks to months after infection. Common signs and symptoms that may extend over time include:
- Shortness of breath or difficulty breathing
- Joint pain
- Chest pain
- Memory, concentration or sleep problems
- Muscle pain or headache
- Fast or pounding heartbeat
- Loss of smell or taste
- Depression or anxiety
- Dizziness when you stand
- Worsened symptoms after physical or mental activities
The predominant pathophysiologic mechanisms of acute COVID- 19 include direct viral toxicity; endothelial damage and microvascular injury; immune system dysregulation and stimulation of a hyperinflammatory state; hypercoagulability with resultant in situ thrombosis and macrothrombosis.
Organ damage caused by COVID-19:
Although COVID-19 primarily affects the lungs, it can damage many other organs as well. Some adults and children experience multisystem inflammatory syndrome after they have had COVID-19. In this condition, some organs and tissues become severely inflamed.
The organ damage may increase the risk of long-term complications. Organs that may be affected by COVID-19 include:
Cardiovascular System: Imaging tests taken months after recovery from COVID-19 have shown lasting damage to the heart muscle, even in people who experienced only mild COVID-19 symptoms. This may increase the risk of heart failure or other heart complications in the future. Persistent symptoms may include palpitations, dyspnea and chest pain. Long-term complications may include increased cardiometabolic demand, myocardial fibrosis or scarring (detectable via cardiac MRI), abnormal cardiac rhythm, increased heart rate, and autonomic dysfunction. Patients with cardiovascular complications during acute infection or those experiencing persistent cardiac symptoms may be monitored with serial clinical, echocardiogram and electrocardiogram follow-up
Respiratory System: The type of pneumonia often associated with COVID-19 can cause long-standing damage to the tiny air sacs (alveoli) in the lungs. The resulting scar tissue can lead to long-term breathing problems. Patient may experience dyspnea (shortness of breath), decreased exercise capacity and hypoxia. Reduced diffusion capacity, restrictive pulmonary physiology, and ground-glass opacities and fibrotic changes on imaging have been noted at follow-up of COVID-19 survivors. Assessment of progression or recovery of pulmonary disease and function may include home pulse oximetry, 6 minute walk test; pulmonary function test (PFT), high-resolution computed tomography (HRCT) of the chest and computed tomography pulmonary angiogram as clinically appropriate
Blood clots and disorder of blood vessel:
COVID-19 can make blood cells more likely to clump up and form clots. While large clots can cause heart attacks and strokes, much of the heart damage caused by COVID-19 is believed to originate from very small clots that block tiny blood vessels (capillaries) in the heart muscle.
Other parts of the body affected by blood clots include the lungs, legs, liver and kidneys. COVID-19 can also weaken blood vessels and cause them to leak, which contributes to potentially long-lasting problems with the liver and kidneys.
People who have severe symptoms of COVID-19 often have to be treated in a hospital’s intensive care unit, with mechanical assistance such as ventilators to breathe. Simply surviving this experience can make a person more likely to later develop post-traumatic stress syndrome, depression and anxiety.
Persistent abnormalities may include fatigue, muscle pain (myalgia), headache, dysautonomia and cognitive impairment (brain fog). Anxiety, depression, sleep disturbances and post traumatic stress disorder (PTSD) have been reported in 30–40% of COVID-19 survivors. Clinically significant PTSD symptoms were reported in approximately 30% of patients with COVID-19 requiring hospitalization, and may present early during acute infection or months later. The pathophysiology of neuropsychiatric complications entails immune dysregulation, inflammation, microvascular thrombosis, iatrogenic effects of medications and psychosocial impacts of infection.
Even in young people, COVID-19 can cause strokes, seizures and Guillain-Barre syndrome — a condition that causes temporary paralysis. COVID-19 may also increase the risk of developing Parkinson’s disease and Alzheimer’s disease.
Other post-acute manifestations of COVID-19 include migraine-like headaches (often refractory to traditional analgesics) and late-onset headaches ascribed to high cytokine levels. In a follow-up study of 100 patients, approximately 38% had ongoing headaches after 6 weeks. Loss of taste and smell may also persist after resolution of other symptoms in approximately one-tenth of patients at up to 6 months follow-up. Many people who have recovered from Covid-19 have gone on to develop chronic fatigue syndrome, a complex disorder characterized by extreme fatigue that worsens with physical or mental activity, but doesn’t improve with rest.
Resolution of acute kidney dysfunction during acute COVID-19 occurs in the majority of patients; however, reduced glomerular filtration rate (eGFR) has been reported at 6 months follow-up
Endocrine Problems (Hormones):
Endocrine complications may include new or worsening control of existing diabetes mellitus, subacute thyroiditis and bone demineralization. Diabetic ketoacidosis (DKA) has been observed in patients without known diabetes mellitus weeks to months after resolution of COVID-19 symptoms. Patients with newly diagnosed diabetes in the absence of traditional risk factors for type 2 diabetes, suspected hypothalamic– pituitary–adrenal axis suppression or hyperthyroidism should undergo the appropriate laboratory testing and should be referred to endocrinology.
COVID-19 also presents risk factors for bone demineralization related to systemic inflammation, immobilization, exposure to corticosteroids, vitamin D insufficiency and interruption of antiresorptive or anabolic agents for osteoporosis.
Prolonged viral fecal shedding can occur in COVID-19 even after negative nasopharyngeal swab testing. COVID-19 has the potential to alter the gut microbiome, including enrichment of opportunistic organisms and depletion of beneficial microorganisms. Studies are currently evaluating the long-term consequences of COVID-19 on the gastrointestinal system, including post-infectious irritable bowel syndrome and indigestion (dyspepsia).
Hair loss is the predominant symptom and has been reported in approximately 20% of COVID-19 survivors
Many long-term COVID-19 effects still unknown
Much is still unknown about how COVID-19 will affect people over time, but research is ongoing. Researchers recommend that doctors closely monitor people who have had COVID-19 to see how their organs are functioning after recovery.
It’s important to remember that most people who have COVID-19 recover quickly. But the potentially long-lasting problems from COVID-19 make it even more important to reduce the spread of COVID-19 by following precautions. Precautions include wearing masks, social distancing, avoiding crowds, hand washing and getting a vaccine.