Lesson 11: How To Test Yourself For Covid Symptoms At Home

How To Test Yourself For Covid Symptoms At Home

It's not ideal to have to test yourself for Covid symptoms yourself, but if testing locations are too far away, or the tests are too expensive or unreliable, you may have no other reasonable option.

There's also the consideration of how often you want to go somewhere and get tested; after all, any test can, at best, only tell you that you don't have the virus at that moment, but what about the next day, or next week?

For these reasons, it's wise to become familiar with how to test yourself for Covid symptoms at home by using the methods that I'll review in this lesson.

Get A Handle On Your Symptoms

You did what you could, but you may have gotten infected anyway. At this point you want to determine if the symptoms you’re experiencing are from Covid. The first thing to do is to review the COVID-19 Symptoms document. [1]

The first thing you have to consider is if you’re being a hypochondriac, or is what you’re feeling symptomatic of a SARS-CoV-2 infection and subsequent COVID-19 health issue? When a pandemic is raging throughout the land, it’s normal to wonder if every cough, sneeze, headache or heartburn is a Covid symptom.

If you’re so sick that you’re completely wiped out, can’t move much, find it hard to breathe and sleep, and are running a fever, assume you’re infected and call your doctor. If your symptoms aren’t so drastic, it’s harder to make a self-assessment, because so many symptoms relating to Covid are shared by many other respiratory illnesses, such as the common flu. 

If you do feel that you’re infected with the virus, try to get a CDC-approved test that’s accurate. In the meantime, it's helpful to be able to make an educated guess about if your symptoms stem from a Covid infection.

What follows is a brief rundown of symptoms. Although in-depth information categorized by five degrees of symptom severity can be found in the COVID-19 Symptoms Guide, most people who get infected with SARS-CoV-2 experience two levels of symptom severity (common and severe symptoms, and three symptom attributes.

The two common levels of symptom severity are:

• Common symptoms, and
• Severe symptoms.

The three common symptom attributes are:

• Neurological symptoms, 
• Gastrointestinal symptoms, and
• Loss of smell (“anosmia”).

Common Symptoms

When the virus does cause symptoms, common indications include fever (100.4°F/38°C body temperature), dry cough, fatigue, loss of appetite, loss of smell and body ache.

Symptoms two to 14 days after exposure (but typically four to five days) include

nausea, neurological (smell, headache, hallucination, taste), blood spots on feet and fingers, hives, viral rashes, pink eyes, fever, cough.

Severe Symptoms

High fever (100.4°F/38°C)

• Severe cough
• Shortness of breath
• Difficulty talking
• Wheezing
• Harsh inhalation
• Drooling
• Excessive drowsiness
• Difficulty drinking 
• Difficulty staying hydrated (no urination 6 hrs or more)

COVID-19 can cause more severe symptoms like high fever, severe cough, and shortness of breath, which often indicates pneumonia, difficulty talking, wheezing, harsh sounding inhalation, drooling, excessive drowsiness, difficulty drinking and staying hydrated which is indicated if you haven’t urinated in 6 to 8 hours.

Neurological Symptoms

• Loss of smell
• Inability to taste
• Muscle weakness
• Tingling/numbness in hands and/or feet
• Dizziness
• Confusion
• Delirium
• Seizures
• Stroke

People with COVID-19 are also experiencing neurological symptoms, such as loss of smell, inability to taste, muscle weakness, tingling or numbness in the hands and/or feet, dizziness, confusion, delirium, seizures and stroke.

Experts do not know how the coronavirus causes neurological symptoms. They may be a direct result of infection, or an indirect consequence of inflammation, or altered oxygen and carbon dioxide levels caused by the virus.

The CDC has added “new confusion or inability to rouse” to its list of emergency warning signs that should prompt you to get immediate medical attention.

Gastrointestinal Symptoms

• Loss of appetite
• Nausea
• Vomiting
• Diarrhea
• Abdominal pain or discomfort

Some people have gastrointestinal (GI) symptoms, such as loss of appetite, nausea, vomiting, diarrhea, and abdominal pain or discomfort associated with COVID-19. 

These symptoms might start before other symptoms such as fever, body ache and cough. SARS-CoV-2 has also been detected in stool, which reinforces the importance of hand washing after every visit to the bathroom and regularly disinfecting bathroom fixtures.

Loss of sense of smell

Increasing evidence suggests that a lost sense of smell (“anosmia”), may be a symptom of COVID-19. This is unsurprising, given that viral infections are a leading cause of loss of sense of smell, and COVID-19 is a virus.

In late May 2020, two out of three people in Germany with COVID-19 lost their sense of smell; in South Korea, 30% of people with mild symptoms who tested positive for COVID-19 reported loss of smell as their main symptom. 

Getting anosmia doesn’t necessarily mean that you’ve got Covid. This can also result from allergies, as well as other viruses, including rhinoviruses that cause the common cold.

Tell your doctor right away if you find yourself suddenly unable to smell. He or she may prompt you to get tested and to self-isolate.

Can COVID-19 symptoms worsen rapidly after several days of illness?

Mild symptoms can last for about one week, then rapidly worsen. If they do worsen, let your doctor know, especially if you or someone you know are having any of these emergency symptoms:

• Difficulty breathing,
• Persistent pain or pressure in the chest,
• Confusion or inability to arouse the person, or
• Bluish lips or face.

At this point you have some idea about whether the symptoms you’re experiencing may be related to Covid. The next step is use three tests to confirm or deny your suspicions.

These are the three tests you can do at home:

1. Health questionnaires that are reliant on you accurately diagnosing and reporting your symptoms;
2. A Pulse Oximeter that measures blood oxygen levels and heart rate; and
3. Respiration Rate — the numbers of breaths you take per minute.

None of these tests are definitive, but your alternatives aren’t great either. Currently, getting an accurate CDC-approved test for coronavirus is difficult, and sometimes expensive, even though many are touted as free. And should they become widely available and inexpensive, and therefore you get tested, you will only know that you weren’t infected on the day of the test. 

What about the next day?

Unless you can test yourself everyday with a scientifically approved test, it’s helpful to be able to have some tools at your disposal that could help indicate if you’re infected.

If the results of the health questionnaires, pulse oximeter or respiration rate indicate that you might be infected, you’ve got sufficient reason to call your doctor.

Test #1: Health Questionnaire

Primary care doctors,  Michael Hochman and Michael Wang, along with several colleagues, developed a simple self-triage tool to help you decide when to treat your symptoms safely at home and when to seek medical help.

It’s very important that those who have moderate symptoms stay at home, rather than flood emergency rooms. Medical providers need to be able to concentrate on the seriously ill, and the vast majority of people (perhaps 80% or more) who come down with COVID-19, especially those under 50, will suffer symptoms that are no more serious than a bad cold or a mild flu.

The focus of this test is on two questions.

Question #1:

Do you currently have symptoms that may be due to COVID-19, particularly a cough, difficulty breathing, feeling feverish as well as, in some cases, diarrhea, muscle aches, fatigue, sore throat, runny nose, or loss of taste or smell?

If you answer “yes”, this is the response:

Your symptoms may be due to COVID-19, although these symptoms may also be due to another type of cold or flu virus. Regardless of whether your symptoms are due to COVID-19 or another virus, the treatment is the same.

Question #2:

Do you have severe symptoms, such as feeling very ill, noticeably short of breath, chest pain, light-headedness or any other worrisome symptoms for which you would typically seek immediate medical attention at an urgent care or emergency room?

If you answer “yes”, this is the response:

Seek immediate medical care. If necessary, call 911. Otherwise call your primary care doctor, or local urgent care facility right away. If possible, call ahead when seeking care to ensure you follow appropriate protocols for minimizing infection spread.

Similar questionnaire-type tests are offered by the CDC self checker and the government of Ontario, Canada’s self-assessment test. 

Test #2: Pulse Oximeter

Emergency rooms measure the oxygen levels of COVID-19 patients with a device called a Pulse Oximeter. I’ll link to a few in the References tab.

Pulse Oximeters work by beaming different wavelengths of light through your finger once it’s inserted into the device. It measures the amount of oxygen in hemoglobin.

Hemoglobin is the protein molecule in red blood cells that carries oxygen from the lungs to the body’s tissues and returns carbon dioxide from the tissues back to the lungs.  

Hemoglobin absorbs varying amounts of light and wavelengths of light depending on the oxygen content of the blood. The Pulse Oximeter provides the percentage of oxygen saturation in the blood.

• Low oxygen levels may indicate that you have pneumonia — and require immediate medical attention — even before you may feel a shortness of breath.
• Normal oxygen levels may indicate that you don’t need to visit a hospital if everything else is OK.

Doctors typically look for a range of 95 to 100% for healthy patients. Oxygen levels below 90% signal a clinical emergency, according to the World Health Organization. [2]

The reason why Pulse Oximeters are a great diagnostic tool is because people with COVID-19 can have pneumonia for days before they develop shortness of breath. Low oxygen levels are a way to detect these cases earlier.

Pulse Oximeter readings are sometimes fickle if you don’t keep your hands still, but the machine itself is extremely reliable.

The New York Times has a detailed article about home use of a Pulse Oximeter. [3] Here’s a summary:

• The device works better with warmer hands than cold hands. And because oxygen levels can fluctuate, consider taking measurements a few times a day. Also try it in different positions, such as while lying flat on your back or while walking. Keep notes to share with your doctor if needed.
• Most health technicians will place the device on the index fingers, but a study of 37 volunteers found that the highest reading came from the third finger on the dominant hand. A close second was the dominant thumb. So if you are right-handed, use the right middle finger. If you are left-handed, use the left middle finger. The difference between fingers is small, so if you prefer the index finger, that’s fine.
• Dark nail polish can affect accuracy of the reading. Very long nails would make it difficult to insert your finger properly in the clip.
• If your number dips to 92% or lower, you should check in with your doctor. But don’t panic. It’s possible that a home monitor could give a faulty reading or be used incorrectly, prompting a patient to seek care unnecessarily. If you or someone in your home shows a very low reading, you may want to test your device on a healthy person to confirm that it is working correctly and discuss it with your doctor.

Before you completely rely on a Pulse Oximeter, read Consumer Report’s pros and cons of relying on it as a COVID-19 infection assessment tool. [4]

Some notable comments:

• Focus on the trend, not the specific oxygen saturation percent reading.
• Some wearable wellness devices have built-in Pulse Oximeters, but they are likely to be even less accurate than home Pulse Oximeters.
• You can get a sense of breathing efficiency without any kind of medical device by measuring your respiratory rate — the number of breaths you take per minute, which brings me to the third way to test yourself at home, respiration rate.

Test #3: Respiration Rate

Measure your respiratory rate by counting how many breaths you take at rest in 30 seconds, and then multiply that by two to get your breaths per minute.

According to the Cleveland Clinic: 

The normal respiration rate for an adult at rest is 12 to 20 breaths per minute. [5] 

As you know, in COVID-19, the virus infects the alveoli, those balloon shaped, one cell thick air sacs that take up oxygen.

Without functioning alveoli, each breath does not remove as much carbon dioxide from the blood, or provide as much oxygen to the blood as it needs to. To make up for the loss of efficiency per breath, the body is forced to do more respirations to provide the same oxygen supply

Therefore, if your alveoli are infected it’s likely that your respiration rate is up. The only way you’d know if this is happening is if you knew your baseline respiration rate; therefore, I suggest you measure it several times before you get sick to get a baseline average.

Your Takeaway:

It’s reasonable to presume that you’ve got COVID-19 if you:

• Are so debilitated you can’t function, and it’s not for any combination of symptoms you’ve ever experienced before.
• Your oximeter rate is below 95%.
• Your respiration rate is above 20 per minute.

Call your doctor if you experience any of the above conditions, or these:

• Fever -- 100.4°F/38°C body temperature
• Severe cough
• Can’t smell
• Confusion
• Unusual weakness and fatigue
• Trouble breathing properly

Next up is Lesson 12, where we'll see that when one part of the immune system doesn't work properly, or at all, there's a downstream effect. A metaphor we can use is dominos. The domino effect occurs when the first responders of the innate immune system are compromised by SARS-CoV-2