When a doctor presses on your ankle with their finger and holds it there for a few seconds, they’re checking for fluid buildup under the skin. This quick test, called a pitting edema check, reveals whether excess fluid is pooling in your lower legs. It’s one of the simplest and most common physical exam techniques, and the results can flag problems with your heart, kidneys, liver, or veins. In some cases, the “squeeze” targets a different area entirely, like the calf muscle, to check for a torn Achilles tendon.
What the Ankle Squeeze Actually Tests
The most common version of this exam involves your doctor pressing a fingertip firmly into the skin near your ankle bone and holding it for several seconds. When they release, they’re watching for a dent, or “pit,” left behind in the skin. If the skin bounces right back, there’s little to no excess fluid. If a visible indentation lingers, fluid has accumulated in the tissue beneath the skin.
This fluid, called interstitial fluid, normally exists in small amounts between your cells. When something disrupts the balance of pressure inside your blood vessels and the surrounding tissue, fluid leaks out of tiny capillaries and collects where gravity pulls it. Because your ankles sit at the lowest point of your body when you’re standing or sitting, they’re usually the first place swelling shows up.
Your doctor may press in more than one spot. A thorough check often includes the lower calf, behind the inner ankle bone, and the top of the foot. Each location can reveal how far the swelling extends up the leg, which helps determine severity.
How Doctors Grade the Swelling
Doctors use a 1 to 4 grading scale based on two things: how deep the dent is and how long it takes to fill back in.
- Grade 1: A shallow dent of about 2 millimeters that rebounds almost immediately. This is mild and often related to standing all day or sitting on a long flight.
- Grade 2: A 3 to 4 millimeter dent that takes up to 15 seconds to disappear. This suggests moderate fluid retention.
- Grade 3: A 5 to 6 millimeter dent that lingers for about a minute. The lower leg typically looks visibly swollen at this stage.
- Grade 4: An 8 millimeter or deeper dent that takes 2 to 3 minutes to rebound. The leg appears obviously distorted, and the cause usually needs urgent investigation.
The grading is somewhat subjective since it relies on visual estimation, but it gives doctors a consistent language to track whether your swelling is getting better or worse over time.
Heart Failure and Ankle Swelling
One of the most important reasons doctors check your ankles is to screen for signs of heart failure, particularly right-sided heart failure. When the right side of the heart can’t pump blood efficiently, pressure builds up in the veins. That elevated venous pressure gets transmitted backward through the circulatory system, all the way down to the tiny capillaries in your legs. The increased pressure forces fluid out of those capillaries and into the surrounding tissue.
Heart failure also triggers the body to retain sodium and water through a cascade of hormonal signals involving the kidneys. This creates a vicious cycle: the heart struggles to move blood forward, venous pressure climbs, the kidneys hold onto more fluid, and the swelling gets worse. Patients with right-sided heart failure, pulmonary hypertension, or problems with the tricuspid valve (between the right chambers of the heart) are especially prone to persistent ankle edema that can be difficult to resolve.
Kidney and Liver Disease
Your kidneys and liver also play a major role in keeping fluid where it belongs. In kidney disease, particularly a condition called nephrotic syndrome, the kidneys leak large amounts of a protein called albumin into the urine. Albumin normally acts like a sponge inside your blood vessels, holding fluid in. When albumin levels drop, fluid seeps out into the tissue.
At the same time, damaged kidneys retain excess sodium and water, adding even more volume to the system. Interestingly, low albumin alone doesn’t always cause swelling. People born without the ability to produce albumin don’t necessarily develop edema, which tells researchers that sodium retention is a critical piece of the puzzle. Both mechanisms together, the protein loss and the sodium retention, drive the swelling that makes ankle checks so informative for kidney disease.
Liver cirrhosis creates a similar pattern. A damaged liver produces less albumin, and the resulting drop in blood protein levels allows fluid to leak into tissue throughout the body, including the legs.
Vein Problems in the Legs
Chronic venous insufficiency is another common explanation. Your leg veins contain small one-way valves that keep blood moving upward toward the heart. When those valves weaken or fail, blood flows backward and pools in the lower legs. Over time, the increased pressure in those veins pushes fluid into the surrounding tissue, causing persistent ankle swelling. You might also notice brownish discoloration of the skin near the ankles, which develops as red blood cells leak from the congested veins and break down in the tissue.
Medications That Cause Swelling
If you’re on certain medications, your doctor may check your ankles specifically to monitor for drug-related side effects. Blood pressure medications in the calcium channel blocker family are one of the most common culprits. These drugs relax blood vessels, which can increase pressure in the capillaries and push fluid into the tissue. The type known as dihydropyridine calcium channel blockers causes this more frequently than others in the same class.
Anti-inflammatory painkillers (NSAIDs) can also promote fluid retention by affecting how the kidneys handle sodium. Other blood pressure drugs, including beta blockers and certain vasodilators, may contribute when used at higher doses. If your doctor notices new ankle swelling during a routine visit, one of their first questions will be whether any of your medications have recently changed.
Checking Pulses Near the Ankle
Not every ankle squeeze is about fluid. Doctors also feel for pulses at two key spots near the ankle: behind the inner ankle bone (the posterior tibial pulse) and on the top of the foot (the dorsalis pedis pulse). They’re pressing firmly enough to feel the artery pulsing beneath the skin, which tells them whether blood is flowing adequately to your feet.
This is a quick screening tool for peripheral artery disease, a condition where narrowed arteries reduce blood flow to the legs. Research shows that when pulses are detectable in both feet, the chance of significant peripheral artery disease drops below 3.5%. If a pulse is weak or absent, your doctor may follow up with a more precise test called an ankle-brachial index, which compares blood pressure readings at the ankle and the arm. They’ll also look at skin color, temperature, and how quickly color returns after pressing on a toenail to build a full picture of your circulation.
The Calf Squeeze for a Torn Tendon
There’s one more squeeze test that involves the lower leg, though it targets the calf rather than the ankle itself. Called the Thompson test, it checks whether your Achilles tendon is intact. You lie face down with your feet hanging off the edge of the exam table, and your doctor squeezes the fleshy part of your calf muscle. Normally, this squeeze pulls on the Achilles tendon and causes your foot to point downward slightly. If the foot doesn’t move at all, the tendon is likely torn. It’s a simple, painless test that gives an immediate answer without imaging.