Five years-and hundreds of millions of cases-after the World Health Organization declared the Covid-19 Pandemia, Scientists are getting a clearer image of how the virus can affect the organism long after the infection seems to have passed.
Some of The effects of the COVID-19 They became evident shortly after the virus began to spread. We immediately understood how mortal that could be an infection, especially for those who suffered from underlying diseases such as diabetes and heart disease. But years of investigation have needed to begin to understand how A covid attack can cause lasting changes, sometimes invisible, in different parts of the body.
Some of these effects, such as the Chronic fatigue and cerebral fog, are considered persistent coviddefined as the symptoms of an infection that persist for at least three months. According to some estimates, 400 million people worldwide have been diagnosed with some form of persistent covid. But an infection can also cause other problems, such as pulmonary and cardiac damage, as well as changes in intestinal microbiomethat are not always recognized as persistent covid, but that can have a lasting effect on our health.
Now we have a clearer idea than there may be behind these changes, including the role of generalized inflammation that COVID can cause. For most people, inflammation refers when the virus disappears. However, In some cases, if inflammation is too intense or persists as a “slow burn” during Too much time, it can wreak havoc in the agency, said Braden Kuo, neurogastroenterologist at the Massachusetts General Hospital.
The lungs
Covid irritates the lungs and can cause long -term problems, such as Respiratory difficulty and persistent cough. In rare cases, you can make Patients develop pneumonia and leave scars and small masses of tissue, called nodules, throughout the lung. Those scars can hinder breathing. Small -scale studies have indicated that more than 10 % of people hospitalized by a Covid infection had pulmonary scars and other problems two years later.
Cause:
The virus invades the respiratory tract cells, which causes inflammation that can attack and sometimes destroy the healthy lung tissue. This can affect the ability of the lungs to transport oxygen to the body. When trying to recover, the lungs form scars, but the scar tissue can harden them and reduce their capacity, causing lasting symptoms such as coughing and difficulty breathing.
The intestine
COVID-19 can cause short-term symptoms, such as nausea, vomiting and diarrhea. But also It can cause chronic gastrointestinal problems, such as reflux, constipation, diarrhea and abdominal pain. These can last months or even years. In a 2024 study, it was estimated that up to 10 % of people had lasting abdominal pain and 13 % gastrointestinal problems a year later.
Cause:
The virus can alter the intestinal microbioma, reducing beneficial microbes and increasing harmful. Inflammation, both by the virus and by the microbial imbalance, can damage the intestinal lining, allowing the filtration of toxins and food particles. This can generate intolerances and immune responses similar to allergic ones. In addition, inflammation can damage the nerves of the intestine, affecting digestion and causing diarrhea or constipation.
The brain
During infection, many patients have headache, dizziness, confusion, difficulty concentrating and memory loss. These symptoms can persist: between 20 % and 30 % of infected people report cerebral fog three months later. Covid can also cause or aggravate disorders such as anxiety and depression.
Cause:
Persistent inflammation damages neurons and inhibits synapse formation. In addition, it can affect areas of the brain related to cognition and emotions. It is suspected that Covid alters the blood brain barrier, which damages the cognitive function. The prolonged presence of viral fragments in the brain has also been detected.
The heart
An infection by COVID-19 can double the risk of cardiovascular events up to three years laterincluding infarcts, strokes, damage to heart muscle and arrhythmias.
Cause:
Infection and inflammation stress can affect the heart, especially in people with previous conditions. Inflammation can damage heart muscle and endothelium, causing clots or plate detachment. This can cause infarcts, arrhythmias or heart failure. Those who were hospitalized have a higher risk. Some studies indicate that blood groups A, B or AB may have more predisposition.
The circulatory system
Patients with persistent covid They can present difficulties for blood return to the heart, which reduces pumping capacity and causes fatigue and discomfort after physical effort.
Cause:
It is suspected that inflammation damages nerve fibers in charge of vascular control. This can alter blood flow. A reduction in muscle capacity to extract oxygen and poor mitochondria functioning has also been observed, which aggravates muscle fatigue.