New observations regarding Covid’s long-term effects

“Small studies have suggested that over 10 percent of people hospitalized with a Covid infection had lung scarring and other issues two years later.

Covid can lead to chronic gastrointestinal problems, like reflux, constipation, diarrhea and abdominal pain. These issues can last for months or even years. In a 2024 study, researchers estimated that bouts with Covid had left as many as 10 percent of people with lasting abdominal pain and 13 percent with gastrointestinal issues a year later.

Studies have found that roughly 20 to 30 percent of people infected with Covid experienced brain fog at least three months after an initial infection. Research also shows that Covid can lead to conditions like anxiety or depression, or exacerbate existing mental health issues. Some researchers also think that areas of the brain involved in cognition and emotion are particularly vulnerable to inflammation, which helps explain why an infection can induce or worsen mental health issues.

But more common, scientists think, is that the virus provokes inflammation that injures the heart muscle. The virus may also damage the cells lining the blood vessels, leading to inflammation there. This could cause a new clot to form or make existing plaque break off and clog a blood vessel. That type of blockage can cause sudden death from a heart attack or lead to downstream damage to heart muscles and other tissue, which can result in heart failure or an arrhythmia

Studies of patients with long Covid show that their bodies have trouble moving blood out of the legs and abdomen and back up to the heart. That can reduce the amount of blood the heart pumps out, causing fatigue, shortness of breath and a feeling of being unwell after exercise.

In some patients with long Covid, it also appears that the muscles are less able to extract oxygen from the blood than normal, hampering their ability to keep up with exercise, Dr. Systrom said. In addition, the mitochondria — the energy-producing powerhouses of cells — may not work properly or at full capacity, delivering another hit to muscle tissue.”