A broken bone heals over weeks, not days: some fractures, such as those in the fingers, heal in 3 to 4 weeks, and others in 6 to 8 weeks or several months [1]. Children's bones generally heal faster; smoking, diabetes, poor nutrition and moving the fracture too early delay healing [2][3]. While you are in a cast, increasing pain, numbness, a change in the colour of the fingers or toes, or being unable to move them means you should seek care without waiting [4][5][6].
How does a broken bone heal?
A fracture needs three things to heal: the broken ends put back into position and kept from moving, an adequate blood supply to the area, and adequate nutrition [3]. Healing takes place in three stages [2]:
- Inflammation stage: starts immediately after the fracture and lasts for several days. Blood clots at the fracture site; the clot provides the initial stability and the framework for new bone
- Bone production stage: the clot is replaced by soft callus made of fibrous tissue and cartilage, which in turn is replaced by hard bone (hard callus). Hard callus is visible on X-rays several weeks after the fracture
- Remodelling stage: goes on for several months. The bone becomes compact and returns to its original shape; blood circulation in the area improves
How long does a broken bone take to heal?
A fracture starts to heal from the moment it happens, but the time is measured in weeks, not days [1][2]. Some fractures, such as those in the fingers, heal in 3 to 4 weeks; others may take 6 to 8 weeks, several months (3 to 6 months on average) or even longer [1]. Bone generally takes 6 to 12 weeks to heal to a significant degree [2]. Recovery from a broken arm or wrist usually takes around 6 to 8 weeks; it can take longer after a severe injury [5].
The time varies with the bone, age and the injury. Some bones, such as the toe bones, have an excellent blood supply; others, such as the upper end of the thighbone near the hip and the scaphoid bone in the wrist, have a limited blood supply [3]. Children's bones generally heal faster than those of adults [2]; older age and complicated open fractures make healing more difficult [3].
Pain usually stops long before the fracture is solid enough to handle the stresses of normal activity [1]. The times specific to fractures of the wrist, ankle, collarbone and hip and to forearm fractures in children are given in the relevant articles; fractures of the foot and toes and stress fractures are also described in separate articles.
What helps a fracture to heal, and what delays it?
Keeping the fracture still is a critical part of treatment [2]. As for diet, what is recommended is a healthy, well-balanced diet that includes protein, calcium, vitamin C and vitamin D; dietary supplements that go beyond the daily requirements are not effective [3]. None of the sources used names a particular food or herbal product that speeds up healing [1][2][3]; foods that contain calcium and vitamin D are listed in the osteoporosis article.
The main factors that slow or prevent healing are [2][3]:
- Movement of the bone ends and putting weight on the limb too soon
- Smoking and nicotine in any form (including e-cigarettes and nicotine gum and patches)
- Diabetes, an underactive thyroid, vascular disease and severe anaemia
- Poor nutrition and low levels of calcium and vitamin D
- Cortisone-type medicines, other medicines that suppress the immune system and anti-inflammatory painkillers; the risks and benefits of these medicines should be discussed with the doctor
- Older age and infection
What do a cast and a splint (half-cast) do?
A cast is the most common type of fracture treatment: many broken bones heal successfully once the bone ends have been repositioned and a cast keeps them in the proper position [1]. Casts and splints hold the bones in place; they reduce pain, swelling and muscle spasm [4]. Some fractures need surgery [1][5]; the removal of plates and screws put in at surgery is covered in a separate article.
A splint, also called a half-cast, provides less support than a cast but is easier to adjust to swelling [4]. In many fresh injuries a splint is applied first; as the swelling subsides a full cast may replace it [4].
Cast care: swelling inside the cast and getting it wet
Swelling from the injury may cause pressure inside the cast for the first 48 to 72 hours and make the cast feel tight; keeping the swelling down lessens pain [4]. The cast must not get wet: moisture weakens the cast, and damp padding next to the skin can cause irritation [4][6]. Points to watch [4][6]:
- For the first 24 to 72 hours keep the arm or leg propped on pillows above the level of the heart
- Move your fingers or toes gently and often; this prevents stiffness
- Place ice in a dry plastic bag and wrap it loosely around the cast at the level of the injury
- In the shower cover the cast with two layers of plastic or a waterproof cover; even when it is covered, do not put it under water or hold it under running water
- Do not pull out the padding; do not break off or trim the edges of the cast without asking the doctor
- If the cast has gone soft, cracked or broken, seek care without waiting
Why does a cast itch, and what eases it?
The sources do not explain the cause of itching in detail; they state only that damp padding and an object stuck inside the cast can irritate the skin [4].
Do not push a coat hanger, a ruler or any other object inside the cast to scratch; this can cause skin sores and infection [4][5][6]. Do not apply powder or deodorant to the itching skin either [4]. A hairdryer on a cool setting can be tried to relieve itching [6]. See a doctor if the itching persists, if something gets stuck inside the cast or if the skin around the cast becomes red [4].
When does the cast come off, and what should you expect afterwards?
A cast or splint stays on until the bone is fully healed and can support itself; depending on the fracture this takes from several weeks to several months [4]. Do not remove the cast yourself: you may cut your skin or disturb healing [4]. The cast is cut with a saw that vibrates but does not rotate; the padding inside protects the skin [4]. The process is quick and painless, although the saw is noisy [6].
When the cast comes off, the skin underneath may look dry and flaky [6]. While you are in a cast, muscle strength and joint movement are lost; the arm or wrist may be stiff and weak [1][5]. Exercises restore muscle strength and joint movement; a physiotherapist can help, although stiffness and weakness can sometimes last several months or more [1][5]. Even afterwards, movement may need to be limited until the bone is solid enough for normal activity [1].
What are delayed union and non-union?
When a fracture takes longer than usual to heal it is called delayed union; when it fails to heal it is called non-union [3]. In a non-union, pain persists at the site of the break long after the initial pain has gone; the diagnosis is made when repeated imaging shows no progress over several months [3]. Keeping the fracture still and bone-stimulating devices applied over the skin are the non-surgical options; at surgery the fracture is fixed again and a bone graft may be used [3].
When not to wait
An increase in pressure inside a muscle that restricts blood flow is called compartment syndrome; it can start suddenly after an injury or when a bandage or cast is too tight, and it needs surgery as soon as possible [7]. Its symptoms are severe pain in a muscle (which may be worse when the muscle is stretched), swelling, numbness, weakness or pins and needles, and tightness or difficulty moving the affected part [7].
If you notice any of the following while in a cast or splint, go to an emergency department without waiting for an appointment [4][5][6][7]:
- Increasing or severe pain and the feeling that the cast is too tight
- Numbness, tingling, burning or stinging in the hand or foot
- Excessive swelling of the fingers or toes beyond the end of the cast
- Fingers or toes that look very pale, white or blue
- Being unable to move the fingers or toes on their own
- A bad smell or discharge from the cast
- A very high temperature or shivering
- A cast that is cracked, broken, soft or loose
Frequently asked questions
- How long does a broken arm take to heal?
- Recovery from a broken arm or wrist usually takes around 6 to 8 weeks; it can take longer if the arm or wrist was severely damaged [5]. Children's bones generally heal faster than those of adults [2].
- Are there foods that help a fracture to heal?
- The sources name no particular food; they recommend a balanced diet that includes protein, calcium and vitamins C and D, and state that supplements beyond the daily requirements are not effective [3]. Smoking and nicotine in any form inhibit bone healing [3].
- When is a half-cast (splint) taken off?
- A splint is often applied first to a fresh injury; as the swelling subsides a full cast may replace it [4]. A cast or splint is worn until the bone is fully healed and can support itself; do not remove it yourself [4].
This article is a general summary; diagnosis and treatment decisions are made by the doctor who examines you.
Sources
- Fractures (Broken Bones). American Academy of Orthopaedic Surgeons (OrthoInfo), 2025. orthoinfo.org
- Bone Healing. American College of Foot and Ankle Surgeons (FootHealthFacts), n.d.. foothealthfacts.org
- Nonunions. American Academy of Orthopaedic Surgeons (OrthoInfo), 2023. orthoinfo.org
- Care of Casts and Splints. American Academy of Orthopaedic Surgeons (OrthoInfo), 2024. orthoinfo.org
- Broken arm or wrist. NHS (nhs.uk), 2023. nhs.uk
- Patient information: A guide to your orthopaedic cast. Calderdale and Huddersfield NHS Foundation Trust, n.d.. cht.nhs.uk
- Compartment syndrome. NHS (nhs.uk), 2026. nhs.uk
This article is general information and does not replace an examination or imaging. If you have symptoms, see a doctor.
More in this area
- Ankle fracture: cast or surgery, and when can you put weight on it?
- Plates and screws after a fracture: do they have to be removed?
- Muscle strains and tears: how to recognise one and how long it takes to heal
- Osteoporosis (bone thinning): how is it detected and how are fractures prevented?
- Stress fracture: what are the symptoms and how does it heal?