Ankle sprains are graded on a three-point scale based on how much damage the ligament has sustained, how much swelling and bruising you see, and how well you can bear weight. A Grade 1 sprain means the ligament is stretched but intact. A Grade 2 means it’s partially torn. A Grade 3 means it’s completely torn. You can get a rough sense of your grade at home by paying attention to a few key signs, though a clinical exam is the most reliable way to confirm it.
The Three Grades at a Glance
Grade 1 is the mildest injury. The ligament fibers are stretched or slightly torn, producing mild tenderness, minor swelling, and some stiffness. You can still walk on it without much trouble, and bruising is minimal or absent. Most people recover in one to three weeks.
Grade 2 is a partial tear. Pain is moderate, swelling is noticeable, and bruising typically appears within a day or two. Walking is possible but uncomfortable, and the ankle may feel unstable when you change direction or step on uneven ground. Recovery usually takes three to six weeks.
Grade 3 is a complete rupture of one or more ligaments. Swelling is severe and develops quickly, bruising is extensive, and putting weight on the ankle is extremely painful or impossible. Recovery takes several months. About 40% of all acute ankle sprains eventually lead to chronic ankle instability, and that risk is highest with Grade 3 injuries.
Swelling, Bruising, and Timing
The speed and spread of swelling is one of the easiest clues you can observe at home. A Grade 1 sprain usually swells modestly around the outside of the ankle, peaking within a few hours. A Grade 2 sprain swells more and often extends across a wider area. A Grade 3 sprain can balloon the entire ankle within minutes, sometimes making it look like you’ve lost all definition of the ankle bone.
Bruising follows a similar pattern. With a mild sprain you may see no discoloration at all. With a partial tear, bruising tends to appear on the outer ankle within 24 to 48 hours. A complete tear often produces deep purple or blue bruising that can travel down into the foot or up toward the shin over the first few days. The combination of visible bruising and significant swelling is a strong indicator that the injury is at least a Grade 2.
The Weight-Bearing Test
Try standing on the injured foot and, if that’s manageable, take four steps. How that feels is one of the most practical indicators of severity. With a Grade 1 sprain, walking feels stiff and tender but doable. With a Grade 2, you can limp along but instinctively shift weight to the other leg. With a Grade 3, putting full weight through the ankle is either agonizing or feels alarmingly loose, as though the joint could give way.
This simple test is also part of the Ottawa Ankle Rules, a set of clinical guidelines that help determine whether you need an X-ray. If you cannot bear weight for four steps, or if you have point tenderness directly over the tip of either ankle bone (the bony bumps on each side) or over the heel bone, imaging is recommended to rule out a fracture.
What Clinicians Check That You Can’t
A healthcare provider can do two hands-on tests that reveal ligament integrity far better than observation alone. The anterior drawer test involves stabilizing your lower leg and gently pulling the foot forward. If the ankle slides forward more than normal, the ligament on the front-outside of the ankle (the one injured in most sprains) is likely torn. This test has a sensitivity between 73% and 96% for detecting lateral ankle ligament damage, and when the examiner also sees pain and bruising, sensitivity reaches nearly 100%.
The talar tilt test involves tilting the foot inward or outward to stress the ligaments on each side. It’s especially useful for injuries on the inner ankle. Its specificity runs between 89% and 95%, meaning a positive result is a reliable signal that the ligament is damaged. These two tests together give clinicians a confident picture of which ligaments are involved and whether the tear is partial or complete.
Which Ligament Is Likely Injured
The vast majority of ankle sprains happen on the outer (lateral) side when the foot rolls inward. Three ligaments sit on this side, and they tend to injure in a predictable order. The one at the front is the most commonly torn. If the force is greater, the ligament running underneath the ankle bone tears next. The one at the back is rarely involved unless the injury is severe.
Inner (medial) ankle sprains are less common because the ligament complex on that side is thicker and stronger. When the inner ligament does tear, the injury is often more serious and can accompany a fracture. High ankle sprains, which affect the ligament connecting the two lower leg bones just above the ankle joint, are a separate category altogether. They take significantly longer to heal than lateral sprains of the same grade.
When Imaging Is Needed
Most ankle sprains don’t require an X-ray. The Ottawa Ankle Rules have been validated for adults and children over five, and they exist specifically to avoid unnecessary imaging. You likely need an X-ray only if you can’t take four weight-bearing steps or if pressing directly on the back edge or tip of either ankle bone, the heel bone, or a bone on top of the foot reproduces sharp pain.
If the clinical exam suggests a Grade 3 tear, or if symptoms aren’t improving on the expected timeline, an MRI or ultrasound can confirm the diagnosis. Recent research shows that ultrasound performs comparably to MRI for grading ligament injuries in the ankle, with no significant difference in the grades detected by each method. Ultrasound is faster, cheaper, and can be done in the office, making it a practical first choice when imaging is warranted.
Recovery and What Each Grade Requires
Grade 1 sprains respond well to rest, ice, compression, and elevation in the first few days, followed by gentle range-of-motion exercises. Most people are back to normal activity within one to three weeks.
Grade 2 sprains benefit from the same initial approach but often require a brace or ankle support for several weeks. Physical therapy focused on balance and strengthening helps restore stability. Expect three to six weeks before returning to sport or demanding physical activity.
Grade 3 sprains present a different challenge. Strong clinical evidence supports short-term immobilization in a below-knee cast for up to 10 days, which produces better functional outcomes than skipping straight to rehabilitation exercises. After that initial immobilization period, structured rehab begins. Surgery is rarely the first option. Most complete tears heal with guided rehabilitation, though the process takes several months and the risk of re-injury remains elevated if rehab is cut short.
Functional Tests That Reveal Lingering Instability
Once you’re past the acute phase, functional performance tests can reveal whether the ankle has truly recovered or whether subtle instability remains. The most widely used are single-leg hop for distance, side-hop tests (hopping sideways over a line as fast as possible), and the Star Excursion Balance Test, where you stand on one leg and reach as far as you can in multiple directions.
These tests matter because pain and swelling can resolve while the ankle still lacks the reflexive stability it had before the injury. If you consistently perform worse on the injured side, targeted balance and strengthening work can close the gap and reduce your chances of joining the 40% who develop chronic instability. Comparing side to side is the simplest version of this: stand on your injured foot with your eyes closed and note how much you wobble compared to the healthy side.