Eyelids and Fingernails: How Smartphone Cameras May Help Diagnose Anemia

by | Sep 5, 2021 | 128, General Medical News, Medical Journals | 0 comments

What if you could test yourself for anemia by simply taking a picture with your smartphone? You can! The smartphone has become an integral part of our lives. If you’re...

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What if you could test yourself for anemia by simply taking a picture with your smartphone? You can!

The smartphone has become an integral part of our lives. If you’re old enough to remember life before them, you may sometimes wonder how you ever managed without one. For example, among thousands of available apps, hundreds manage health. 

Now your smartphone has a new function—a diagnostic tool for anemia. Recent studies have shown that pictures of the inside of your lower eyelid or your fingernail’s nail bed can detect signs of anemia. 

Given that almost everyone from the young to the old has a smartphone, this new technology expands access to medical care and early detection of disease. 

About Anemia

Anemia is a low level of hemoglobin, the part of red blood cells that delivers oxygen. The most prevalent cause is iron deficiency, but causal factors may include other vitamin deficiencies, disease complications, infection, and genetics. The condition varies from short to long term and from mild to severe or life-threatening. 

According to the World Health Organization, there are almost two billion people in the world with some form of anemia, and 83 million of those people live in the United States. In a study conducted between 2003 and 2012, the National Health and Nutrition Examination Surveys found that about 5.6% of the U.S. population had anemia, and 1.5% had moderate to severe anemia. The groups at highest risk were the elderly, children, pregnant women, and women of childbearing age. 

The most common symptoms of anemia are fatigue, weakness, and dizziness. Depending on the type of anemia, symptoms may also include headache, difficulty breathing or mentally focusing, as well as chest pains, pale skin, and an irregular heartbeat

Traditional diagnosis of anemia requires a complete blood count (CBC). Such a requirement involves professional technicians drawing blood then using chemical reagents and complex laboratory equipment to produce results that can take hours or days to process. The process, however, can be expensive for people without adequate medical coverage and difficult to access for people in specific rural or urban settings. 

Smartphones and Healthcare

It is estimated that by 2019, 36 percent of the world’s population had smartphones, including people of every socioeconomic status. Moreover, this number was expected to increase each year faster than the world’s population growth rate. 

For healthcare professionals, medical apps offer new options for improving patients’ health and the ways they deliver services. Even the Food and Drug Administration (FDA) encourages consumers and healthcare providers to use these apps to distribute and obtain important health information.  

Medical apps can enhance communication between you and your doctor, provide an inexpensive way to help manage chronic health issues, and empower you to be better informed and in charge of your health. For example, instead of just providing your doctor with a list of symptoms, you can collect and report your data. In some instances, you can bypass expensive appointments and tests therefore accelerating the diagnostic process.

Recently scientists have developed new methods for diagnosing anemia with your smartphone camera — simply take a picture of your inner lower eyelid or your fingernail’s nail bed, and the software tells you whether you may have anemia. You then share this with your doctor. Compared to the CBC test, this new method is inexpensive, noninvasive, and available on demand. As a result, it gives you a more significant role in your care.

Inside the Lower Eyelid

In a recent study, a picture taken with a smartphone camera of the inside of the lower eyelid can predict anemia with an accuracy rate of approximately 72 percent. During the study’s Phase 1, researchers took smartphone pictures of the inner lower eyelids of 142 patients. They used these pictures to create an algorithm comparing images to hemoglobin levels.

During Phase 2, they tested the algorithm on 202 additional patients. Results showed that their model accurately predicted anemia at the rate of 72.6 percent. However, the accuracy rate for predicting severe anemia (severe enough to require a blood transfusion) was higher: 86.0 to 94.4 percent. The one limitation researchers cited was variation in image quality. Not all smartphones are alike, after all. 

This method works because hemoglobin is a strong chromophore—the part of a molecule that gives it its color—and is available for spectroscopic evaluation. By employing spectroscopic analysis, the software detects hemoglobin through its absorption of light. The result is hemoglobin levels as measured by a spectrum of light signals. 

The inner eyelid membrane is free of blood vessels and tissues that interrupt the transmission of light. Using this method does not require medical expertise. You simply expose the inside of your lower eyelid, take a picture, and the software does the rest. The next step involves creating a smartphone app that combines image collection and evaluation. 

Fingernails’ Nail Beds

The National Institute of Health (NIH) awarded Sanguina, Inc. third place in the 2020 NIH Technology Accelerator Challenge (NTAC) for its smartphone anemia app, AnemoCheck Mobile. Researchers developed an algorithm that accurately detects signs of anemia by taking smartphone pictures of a patient’s fingernail nail beds and evaluating the color. 

This new app was tested on 100 volunteers, both with and without anemia. After volunteers took pictures of their fingernails, the app analyzed the pictures. As a result, it accurately identified 97 percent of the volunteers with anemia.

AnemoCheck Mobile is another noninvasive diagnostic tool you can use at any time to track your condition and participate more fully with your doctor. For example, you can measure your blood hemoglobin levels and monitor changes in those levels over time. 


With the ever-increasing cost of healthcare looming over us all, using something as simple as a smartphone camera as a diagnostic tool is a welcome addition to more elaborate testing methods. It is readily accessible to anyone with a smartphone, easy to use, and inexpensive. In addition, it does not require blood to be drawn, and results are almost immediate. 

Please keep in mind, however, that this technology is still new and not 100 percent accurate. It should complement, not replace, traditional medical care. Even if your smartphone indicates that you may have anemia, it is still essential to ask for a second opinion from a specialist.

In a device no bigger than a kitchen sponge, a device used for games and social media, you have a powerful tool for collaborating with your doctor and taking on a greater role in your healthcare. 


  1. https://www.medicalnewstoday.com/articles/how-smartphone-cameras-may-be-used-to-detect-anemia   
  2. https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0166635   
  3. https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0253495  
  4. https://www.reuters.com/article/us-health-anemia-smartphones/smartphone-app-could-screen-for-anemia-idUSKBN1O42R8  
  5. https://bme.gatech.edu/bme/news/smartphone-app-anemia-showcased-ntac-challenge  
  6. https://sicklecellanemianews.com/2020/05/28/smartphone-app-may-help-assess-anemia-using-eyelid-pictures/  
  7. https://www.mayoclinic.org/diseases-conditions/anemia/symptoms-causes/syc-20351360  
  8. https://www.fda.gov/medical-devices/digital-health-center-excellence/device-software-functions-including-mobile-medical-applications

Gaye Newton

Gaye Newton