Not reliably. Some studies find lower heart rate variability (HRV) in people with long COVID, but the evidence is early and mixed, and HRV cannot diagnose long COVID or POTS. A wearable can show how your own heart rate and HRV change over time, which may be useful to bring to a doctor, but the diagnosis rests on your symptoms and on tests done in a clinic.
What long COVID and POTS are
Long COVID, which the World Health Organization calls post-COVID-19 condition, has a consensus definition. It applies to people who had a probable or confirmed COVID-19 infection and have symptoms, usually from three months after it began, that last at least two months and cannot be explained by another diagnosis (Soriano and colleagues, 2022). Common symptoms include fatigue, shortness of breath and problems with thinking, and they can come and go.
POTS (postural orthostatic tachycardia syndrome) is a condition where the heart races on standing. A 2015 expert consensus defines it as frequent symptoms on standing, such as light-headedness or palpitations, with a heart rate rise of at least 30 beats a minute (40 for ages 12 to 19) when moving from lying down to standing, and without a fall in systolic blood pressure of more than 20 mmHg (Sheldon and colleagues, 2015). Fatigue and exercise intolerance are also common. Onset can follow a viral infection (Vernino and colleagues, 2021).
Neither definition uses HRV.
What studies show about HRV after COVID-19
- A 2023 review found 11 studies with 2,197 people that compared HRV in people who had recovered from COVID-19 or had long COVID with people who had not had it (Suh and colleagues, 2023). Most found lower SDNN SDNN The standard deviation of all NN intervals in a recording, in milliseconds. It measures overall variability, and its value depends strongly on how long the recording lasts. More about SDNN and lower parasympathetic Parasympathetic nervous system The "rest and digest" branch of the autonomic nervous system. It slows the heart, mainly through the vagus nerve, and drives most of the beat-to-beat variation in HRV. More about Parasympathetic nervous system (calming) activity after COVID-19. But all were snapshots in time, their quality was not optimal, and the authors called for longer studies.
- A 2026 meta-analysis pooled 11 studies with 593 people with post-COVID-19 condition and 565 healthy people, all measured more than three months after infection (Schoene and colleagues, 2026). HRV tended to be lower in the long COVID groups, but none of the pooled differences in SDNN, RMSSD RMSSD Root mean square of successive differences: an HRV metric built from how much each heartbeat interval differs from the next. It mainly reflects vagal activity. More about RMSSD or the LF/HF ratio LF/HF ratio LF power divided by HF power. It was proposed as a gauge of balance between the sympathetic and parasympathetic systems, but research shows it cannot measure that reliably. More about LF/HF ratio was statistically clear. The studies varied a lot, and 9 of the 11 had a high risk of bias.
So a link is possible, but it is not established, and these group studies say nothing about how one person’s HRV will behave. A German study of 24-hour recordings in people with long COVID is described on our page about HRV when you’re sick.
What a wearable can and cannot show
Wearables can follow your own numbers against your own baseline Baseline Your own usual HRV level and range, built from weeks of readings taken the same way. Comparing a reading with your baseline says more than comparing it with other people. More about Baseline . In a US study of people who shared smartwatch and fitness tracker data, 234 had COVID-19 (Radin and colleagues, 2021). Their resting heart rate Resting heart rate How many times your heart beats per minute while you are fully at rest. For adults it is usually 60 to 100 beats per minute, and lower in well-trained athletes. More about Resting heart rate first dipped, then stayed above their usual level for an average of 79 days after symptoms began. In 32 people (about 14%), it stayed more than 5 beats a minute above baseline for over 133 days. This study tracked resting heart rate, not HRV.
| A wearable can | A wearable cannot |
|---|---|
| Show your resting heart rate and HRV against your own baseline | Diagnose long COVID or POTS |
| Show, on some devices, that your heart rate jumps when you stand up | Measure blood pressure on standing, which is part of the POTS test |
| Give you a record to bring to an appointment | Rule out other causes, such as thyroid problems or the effects of medicines |
| Show broad trends over weeks | Tell you that you have recovered |
A clinician makes the POTS diagnosis, and the evaluation also looks for related conditions and for others that can mimic POTS (Vernino and colleagues, 2021). The 2015 consensus does not recommend extra autonomic testing as a routine step (Sheldon and colleagues, 2015).
Go deeper Why HRV is a poor fit for POTS
POTS is defined by how your heart rate responds when you stand up. Most wearables report HRV at rest, often during sleep, so they miss the moment that matters. HRV also falls with poor sleep, illness, alcohol and many medicines, and a low number cannot tell these apart.
Using your data sensibly
- Compare with your own baseline. If you have data from before your infection, it is the best yardstick. See HRV vs resting heart rate for how the two signals relate.
- Log symptoms next to the numbers. Note dizziness, a racing heart, fatigue and bad days. Doctors diagnose from symptoms, and a dated log helps.
- Don’t treat a return to baseline as a cure. Go by how you feel and what your doctor finds.
- Step back if tracking adds to your worry. Weekly averages are enough.
When to see a doctor
See a doctor if fatigue, breathlessness, problems with thinking or a racing heart last for weeks after an infection. Also see a doctor if you feel dizzy, light-headed or faint when you stand up, or your heart races every time you stand. Bring your symptom log and, if you have one, your heart rate trend.
Get emergency help for chest pain, fainting, trouble breathing or confusion, whatever your wearable shows.