Signs That You May Have Had COVID-19: What Research Shows

Angelica Balingit
More than 190 million people have developed COVID-19 since late 2019, according to the World Health Organization (WHO). Many other people have likely had the disease but never received a confirmed test result.

You may have had COVID-19 already without knowing it, although it’s impossible to know for sure unless you undergo an antibody test. And even a positive antibody test comes with a small chance of a false positive.

The most likely way to know that you had COVID-19 is if you had typical COVID-19 symptoms and received a positive diagnostic COVID-19 test when you were sick. But even “gold standard” PCR tests come with a chance of a false negative result, meaning you have COVID-19, but the test results indicate you do not.

If you didn’t receive a positive COVID-19 test when you were sick, it’s harder to know if you had the disease.

There are no sure signs that you already had COVID-19. But there are some general symptoms you may have experienced, such as

pink eye
loss of taste or smell
fatigue

Keep reading as we look at these signs in more depth

Signs that you may have already had COVID-19

COVID-19 can affect many different parts of your body and cause general symptoms that have many potential causes. Some people with COVID-19 don’t develop any symptoms.

It’s impossible to know if you had an infection for sure without a positive COVID-19 test, but here are some of the potential signs.

You developed typical COVID-19 symptoms

Everybody experiences COVID-19 differently, and symptoms can mimic those of other respiratory infections. If you developed any of the most typical COVID-19 symptoms, especially after being in close contact with a someone who had COVID-19, it may be a sign that you had it, too.

According to the Centers for Disease Control and Prevention (CDC)Trusted Source, the following are the most reported symptoms:

body aches
stuffy nose or runny nose
cough
diarrhea
fatigue
fever or chills
headache
nausea
new loss of taste or smell
shortness of breath or trouble breathing
sore throat
vomiting

COVID-19, the common cold, and flu can be difficult to tell apart. Sneezing isn’t a symptom of COVID-19 and may indicate you had a cold or allergies. Shortness of breath isn’t a typical flu symptom but is one of the more common COVID-19 symptoms.

You had pink eye or other eye symptoms

COVID-19 is thought to enter your cells through receptors for the enzyme called angiotensin converting enzyme 2 (ACE2). The virus enters these receptors by tricking your body into thinking it’s the ACE2 enzyme.

ACE2 receptors are found in various parts of your eyes, such as your retina and the epithelial cells that line your eye white and eyelid.

Some people with COVID-19 develop eye symptoms like:

dry eyes
pink eye
swelling
excessive tearing
increased eye secretions

Eye symptoms are usually accompanied by more typical COVID-19 symptoms, but they may appear alone in some people.

You temporarily lost your sense of taste or smell

Loss of taste or smell is commonly reported in people with COVID-19. A review of studiesTrusted Source found that loss of taste or smell was reported in 47 percent of people and was most common in people with mild to moderate disease.

Some people with COVID-19 also experience a distortion of these senses. Symptoms affecting taste or smell seem to often appear before other symptoms.

An August 2020Trusted Source study found that in a group of 11,054 people with COVID-19, symptoms affecting smell and taste appeared before general symptoms in 64.5 and 54 percent of cases, respectively.

You developed a fever first

COVID-19 symptoms often show up in a particular order. In a 2020 study published by the University of Southern California, researchers analyzed the development of symptoms in 55,000 people with COVID-19 and compared them to the symptoms of 2,000 people with influenza.

They found that influenza most commonly started with a cough, while the initial symptom of COVID-19 was most likely to be a fever.

A wide range of initial symptoms of COVID-19 have been reported in scientific literature. Just because you didn’t develop a fever first doesn’t necessarily mean you didn’t have COVID-19.

You’re experiencing long-haul symptoms

Some people who develop COVID-19 have symptoms that persist for weeks or months after their infection. These symptoms have been referred to as long-haul symptoms.

Young adults, children, and even people with mild disease can develop long-haul symptoms. It’s not clear why some people develop long-haul symptoms, but it’s thought long-term tissue damage and inflammation may play a role. Some of the most reported symptomsTrusted Source include: