Lateral Ankle Sprain
Reviewed by Andrew Schox, BSc(Hons) PGradDipPod MPod, October 2026
A lateral ankle sprain is an injury to the ligaments (tough bands that hold bones together) on the outer side of your ankle. It usually happens when your foot rolls inwards. It is very common: about 8 per cent of people have one, and it is the most common muscle and joint injury in people who are active. You will usually have pain, swelling and bruising on the outside of your ankle. With the right care, most sprains get better, but healing is often not complete unless you do proper rehabilitation.
What is it?
A lateral ankle sprain is an injury to the ligaments on the outer side of your ankle. Ligaments are tough bands of tissue that hold your bones together. When you roll or twist your ankle, these bands can stretch or tear.
The ligament most often hurt is the anterior talofibular ligament, or ATFL. It sits at the front of the outer ankle. This is the most common type of ankle sprain.
Who does it affect?
Anyone can sprain an ankle. About 8 per cent of people have one. It is also the most common muscle and joint injury in people who play sport, and about 40 per cent of all ankle injuries from an accident happen during sport. Indoor and court sports carry the highest risk.
Sprains happen more often in females than males, in children than teenagers, and in teenagers than adults. Many people get a second sprain: it can happen again as often as 80 per cent of the time in people who play high-risk sports.
Signs and symptoms
You will usually have pain on the outer side of your ankle, in front of and below the outer ankle bone. Swelling and bruising are common, and walking can be hard. Swelling can take months to settle fully. Your ankle may also feel unstable, as if it could give way.
A mild sprain may only be sore and a little puffy. A severe sprain can be very swollen and tender, and you may not be able to put weight on it at all.
What causes it?
Most sprains happen when your foot points down and rolls inwards. This stretches or tears the ligaments on the outer side of your ankle.
Common triggers include:
- a sudden change of direction
- twisting on a planted foot
- landing awkwardly or being hit during sport
- walking or running on uneven ground
- missing a step on the stairs, which is more likely in high heels
Occasionally the foot rolls the other way and strains the ligaments on the inside of your ankle. If your foot was forced outwards or upwards instead, your ankle needs a proper check, because it could be a less common ligament injury or a break.
How is it diagnosed?
Your podiatrist will ask how the injury happened and then examine your ankle. They will look at swelling and bruising, press along the ankle to find the sore spots, and test how well the ankle moves and holds steady. One test, where the foot is gently drawn forward (the anterior drawer test), works best 4 to 5 days after the injury. So your podiatrist may check you again after a few days.
The main thing to rule out is a broken bone. Clinicians use a checklist called the Ottawa ankle rules. It is very good at showing that you don't have a break. But it also flags many people who don't have one, so a flag alone doesn't always mean you need an X-ray. Your practitioner will use their judgement as well.
An MRI scan is only used if a more serious injury is suspected, such as damage to the joint surface or a hidden break.
Treatment
Most people do best with early, guided movement and support, not a long rest in a cast.
Looking after it at home
In the first couple of days, avoid heat (such as hot baths and heat packs), alcohol and massage, as these can increase swelling. Don't wait for the pain to go before you start moving the ankle. Early exercise is a key part of getting better, and your practitioner can show you what to do.
Treatment from your podiatrist
The best-supported care is a brace or tape for 4 to 6 weeks, together with exercises, starting early. This works better than rest in a cast. Exercises should train your balance, your ankle's quick muscle reactions, and your strength. Balance exercises throughout your recovery lower the chance of spraining it again.
For a severe sprain, a short time in a cast or rigid support, for less than 10 days, can ease pain and swelling. Then you move on to the brace or tape and exercises. Four weeks or more in a cast is not recommended, because results are poorer.
Other options
If your ankle is clearly unstable at the first check, or hasn't improved after 2 weeks of care, a doctor should look at it. If pain or instability carries on after your first treatment, you may be referred to an orthopaedic specialist (a doctor who treats bone and joint problems). The same goes for injuries such as a torn tendon or damage to the ligaments above the ankle joint.
Recovery
Recovery is often slower and less complete than people expect. About 40 to 55 per cent of people still have symptoms six months later. Up to 70 per cent are reported to develop long-term ankle instability, and an estimated 50 to 70 per cent of people don't get proper rehabilitation after the first sprain.
When the pain and swelling settle, it doesn't mean your ankle has fully recovered. It may still be loose or have poor balance control, which makes it easier to hurt again. Going back to hard activity too soon can make repeat sprains and ongoing ankle problems more likely. Build up gradually, in stages, and keep doing your exercises after the pain has gone.
Preventing it
The best protection is to start guided exercises early and keep them up, with balance and strength work. Getting a first sprain properly rehabilitated matters, because repeat sprains can lead to a loose, unreliable ankle.
A brace is a good option to help prevent more sprains, especially in sport. Ask your podiatrist whether one suits you. Take extra care on uneven ground, on stairs and when you change direction quickly.
When to see a podiatrist
Book an appointment if
Your ankle hasn't improved after 2 weeks, or the pain is getting worse. You have numbness or pins and needles that haven't improved after 2 weeks. Your ankle feels loose or keeps giving way. You have bruising on the sole of your foot. You are not back to normal after 6 weeks. Book an appointment with your podiatrist, or see your GP or physiotherapist.
Seek prompt assessment if
Call your local emergency number if your foot or toes turn cold and pale or blue after the injury, with numbness or pain, or if you can't move your foot or toes. Go to the nearest emergency department if your ankle looks out of shape or is pointing at an odd angle. See your GP or another doctor today if you can't put your full weight on your ankle and take 4 steps straight after the injury, or can only manage a few steps. Do the same if you heard a crack when you hurt it, it bruised or swelled a lot straight away, you have a known blood disorder, or there is a wound that may go into the joint. A very high temperature, or feeling hot and shivery, also means seeing a doctor today, as it can be a sign of infection. If your GP can't see you today, go to an urgent care clinic or an after-hours GP. If a child has hurt their ankle, have a GP or other health professional assess it promptly, because growth plate injuries and breaks can look like a sprain.
Frequently asked questions
Why does my ankle keep giving way?
Repeated sprains can leave the ankle loose and slower to react. This is called chronic ankle instability. It can involve poor balance, weaker muscles and a weaker sense of where your ankle is in space. Rehabilitation with balance and strength exercises helps, and a brace can be useful for sport. Ask your podiatrist for a plan.
What do the grades of a sprain mean?
Sprains are graded from 1 to 3. Grade 1 is a mild stretch of the ligament, with no looseness in the joint. Grade 2 is a partial tear, also without looseness. Grade 3 is a complete tear, and the joint is unstable. The grade helps your practitioner plan your care, including whether a short time in a cast is needed.
Is a tubigrip or elastic bandage enough?
Not on its own. A proper ankle brace or tape works better than a compression bandage or tubigrip. Your podiatrist can fit or apply the right support and show you the exercises to go with it.