By Helen Shih, PhD

Flow-of-Light Natural Health

Light up your body, mind, & soul

COVID-19 Self-Monitoring

Self-monitoring at home during COVID-19 outbreak

Who may need this procedure?

Anyone who wants to monitor their health conditions during the COVID-19 outbreak, especially those who are at a high risk of infection.

Why do I need this?

  1. To establish body baseline conditions and reference levels before you get sick, by monitoring blood oxygenation level SPO2 (related to lung function), Basal Body Temperature BBT (to detect the possible start of fever), and other respiratory and body conditions;
  2. To track if these conditions change over time and how your body may respond to possible infection of COVID-19 or other sources.
  3. In case you are infected, to see if symptoms are worsening over time and use the data to guide your decision when to seek medical care (these data will be helpful to your doctors too).
  4. In case you are recovering, to see if symptoms are getting better and how you recuperate.

How long does this take? 

Approximately 5 mins.

What do I need?

  1. Finger pulse oximeter (FPO) or similar pulse oximeter devices that can measure blood oxygenation level SPO2;
  2. BBT thermometer (this type of thermometer is more precise and provides 0.01C or F reading, whereas regular body thermometer has a bigger temperature measurement range with a precision of only 0.1C or F);
  3. Timer or clock (available on your smartphone) to measure breathing rate.
  4. Other devices you regular use for monitoring, especially if you have other underlying health conditions, such as diabetes, cardiopulmonary diseases, cancer, etc; 
  5. A notepad or spreadsheet to record the data (a Google sheet is attached for reference).

How much does it cost?

Low-cost FPO is ~$15-$30; BBT thermometer is ~$10-$30.

Are there any other benefits?

1. To learn how to monitor your own health conditions and become more aware of your body’s reaction should infection occurs; An added benefit is to learn the basics of physiology and how to do these measurements properly, which may be helpful in other situations;

2. To reduce the volume of patients going to doctor’s offices and hospitals, so they are not overwhelmed and have more time to take care of severely ill patients (“Flatten the Curve”).


How to do this procedure?

Step 1. SPO2:  In the morning when you wake up, use FPO to measure your resting SPO2 level. It is very simple and takes less than a minute. Add other time points of the day if needed, such as at bedtime. SPO2 level may change with exercise and other body conditions. Try to keep the measurement as consistent as possible, for example, by using the same device, same finger, same body condition and situation during the day (Pls check FPO instruction and other reference materials). Normal SPO2 is 95%-100%. Watch the trend of SPO2 if you notice any discomfort or symptoms. Continuous decrease of SPO2 or when it drops below 95% can indicate impaired lung function. Note: Young healthy adults may have normal and stable SPO2 levels even when symptoms get worsen; children may have higher SPO2 levels and respond differently to infection than adults; elderly or people who have existing health conditions may have a low SPO2 to start with. Nail polish may affect readings.

Step 2. BBT measurement: In the morning after the SPO2 measurement, use a BBT thermometer to measure your resting body temperature. It takes a few minutes to do (before you take shower/bath, exercise or food/drink as it may alter BBT). Add other time points of the day if needed, such as at bedtime. BBT may change with activities and other body conditions such as female ovulation. Try to keep the measurement as consistent as possible, for example, by using the same device, same measurement location, same body condition and situation during the day (Pls check BBT thermometer instruction and other reference materials). Your normal BBT is different from other people and should be very stable. Watch the trend of SPO2 if you notice any discomfort or symptoms. A continuous increase of BBT may indicate the onset of fever or trigger of body immunity reaction. Clinical experiences show that approximately 90% of patients infected by COVID-19 had a fever.

Step 3. Respiratory and Other Conditions

During the time when you measure BBT in the morning, observe your resting breathing condition and measure your normal breathing rate (number of breaths per minute). The normal range is 12 - 20/min for healthy adults. Establish a baseline level when you are healthy. Physical activities and other body conditions can change your breathing rate, so please keep the measurement as consistent as possible. Patients with the infection and pneumonia may have difficulty in breathing, shortness of breath, discomfort or pain in chest, and/or faster breathing rate. Cough occurred to about 72% of the patients, according to current experiences. 

Monitor other symptoms you may have, such as digestive, neurological, cardiovascular, and other conditions. If you have existing health problems, especially cardiopulmonary, metabolic or immunity orders, cancer, etc, continue to watch those conditions too.


Record your data in the sheet, including data and time of the measurement, plus any other note. You can include other tests if needed, such as resting heart rate, resting blood pressure, at the same time as other measurements. These measurements may be important for elder people or those who have other health conditions or impaired immunity or are at a higher risk than others. A cohort of patients may also develop muscle pain, fatigue, headache, diarrhea or other problems. Please record these notes if needed.  


Mild symptoms that do not get worse over time may not affect any of the factors above. A COVID-19 test has to be done to tell if you are infected by this virus. If the symptoms and data are getting worse over days, then you need to pay close attention and seek medical care as soon as possible. Medical literature so far says that severe symptoms will develop within 4-7 days after the symptom onset, but only occur to less than 20% of COVID-19 infected patients.

How do I use the data?

1. If you have not been tested or have been tested negative for COVID-19: When you find any indicators from the above procedure getting worsen from your healthy baseline, or if you have any other symptoms listed by CDC test guideline (see Reference), or for any other reason suspect you are being infected (such as you interacted with others who have been infected), please arrange COVID-19 test if it is available, and start to isolate yourself from other people immediately;

2. If you have already been tested positive and asked to be in self isolation: Watch your symptoms carefully and monitor the results from the above procedure.  If the results are getting worsened over time or suddenly worsened, please call your doctors and visit hospitals.


Disclaimer: The above is a simple procedure you can do at home. It is not meant to substitute professional medical advice, tests, monitoring, and hospital care. Please talk to your doctors if you have questions or concerns.



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6. Pneumonia Symptoms and Diagnosis, American Lung Association,

7. Pneumonia, National Heart, Lung, and Blood Institution

8. CDC Guideline on COVID-19: