It may be a little easier than decoding the color of your urine—but experts say you shouldn’t ignore what’s in the toilet bowl, either.
In July, temperatures were well above average across most of the U.S.—and August isn’t shaping up to be any better. During bouts of extreme heat, staying hydrated is crucial to mental and physical health.
To help you determine if you’re getting enough fluids, or if you could stand to have another glass or two of water, a TikTok tip—known as the “skin pinch” test—has resurfaced on the app, and it’s getting quite a bit of buzz.
The video, initially shared last summer, was posted by TikTok doctor Karan Rangarajan, MRCS, MBBS, a surgical doctor with the National Health Service in the U.K., and it shows a person squeezing the top of their finger to determine how hydrated (or dehydrated) they are.
“This is known as the ‘skin pinch’ or skin turgor test,” Dr. Rangarajan said in the video. “The more hydrated you are, the more elastic your skin will be and it will bounce back immediately after pinching it. If you’re dehydrated the skin loses its elasticity and it takes a while to return to normal, and it’s more likely to tent up.”
The skin pinch test seems like a fast and uncomplicated way to know if you need more water, but is it the best way to see if you’re dehydrated? Here’s what to know.
How Does the Skin Pinch Test Work?
The skin pinch test is used to measure the skin’s elasticity, or its ability to stretch and bounce back. It can also be used as a way to assess dehydration.
“It is known as poor skin turgor when the skin doesn’t bounce back within a second or two,” nutritionist Kathryn Piper, RDN, LD, told Health. “Poor skin turgor can be an indicator of dehydration.”
According to nutrition and wellness expert Samantha Cassetty, MS, RD, the test is often used in healthcare settings to get a quick assessment of whether a patient may need more fluids, especially when there’s not enough time to evaluate lab tests or other metrics.
“It’s definitely legit and used in healthcare settings when dehydration is suspected,” Cassetty told Health. “However, practitioners look at the full clinical picture in addition to skin turgor.”
How Accurate Is the Skin Pinch Test?
Healthcare professionals use the skin pinch along with other medical tests because it’s painless and non-invasive, but it’s not as precise as other measurements and there are no clinical standards for how it’s implemented.
“There’s no gold standard for practicing it,” Cassetty said. “Some practitioners may pinch the back of the hand, while others may use other areas; and sometimes the pinch could be two seconds, while some clinicians may hold your skin longer.”
The test may also not be useful or effective for everyone, including older adults and people with certain health conditions.
As people age, for example, skin elasticity decreases, regardless of hydration status. “An older person’s skin may take about 20 seconds to bounce back, even if they are not dehydrated,” Piper said.
In patients with low blood volume, the skin pinch test may also have reduced accuracy. “About 70% of people with long COVID have autonomic nervous system dysfunction and may have low blood volume,” Cassetty said. “This test is not helpful for people with low blood volume or connective tissue disorders.”
Trying the Skin Pinch Test
The skin pinch test is pretty safe and there’s no harm in testing yourself, but since it’s not the most precise method, the results should be taken with a grain of salt and used in tandem with other dehydration identifiers.
“I don’t see a harm in using this test as one way to assess hydration,” Piper said. “As a dietitian, I recommend monitoring the color of your urine to ensure you are staying hydrated.” Urine should be light yellow or straw-colored; “light-colored lemonade” is also a good color match, according to Piper.
Some other key indicators that you’re not getting enough fluids include feeling very thirsty, having dry skin or a dry mouth, or not sweating or urinating as much as usual.
Instead of analyzing how dehydrated you might be, Cassetty suggests taking a more proactive approach to hydration. “I think you’re better off using strategies to stay hydrated rather than reacting to potential dehydration,” she said.
The Centers for Disease Control and Prevention (CDC) recommends having water with meals and improving the taste of water with fruit like lemon or lime slices to up your fluid intake.
“To help remind you to drink more water, use a 20-ounce water bottle and keep it nearby,” Cassetty added. “As a rule of thumb, aim to refill at least four times a day and drink an additional glass of water at each meal.”