Heel pain while lying on your back is almost always caused by the concentrated pressure between your heel bone and the surface you are resting on, sometimes combined with an underlying condition that makes that pressure intolerable. The heel is one of the body’s most prominent bony contact points, and when you lie supine, your full lower-leg weight funnels down into a small patch of skin and tissue pressed against the mattress. For many people, this mild compression goes unnoticed. But if your heel’s protective fat pad has thinned, your Achilles tendon is inflamed, or your plantar fascia is already irritated, even ordinary mattress contact can produce sharp or aching pain that keeps you awake.
Why Your Heels Are Pressure Hot Spots
When you lie face-up, your body makes contact with the mattress at a few predictable places: the back of your head, your shoulder blades, your sacrum, and your heels. Unlike the broader, fleshier areas of your back and buttocks, the heel is a relatively small, bony protrusion with limited soft tissue covering it. That means the force of your leg’s weight gets compressed into a small area, creating high interface pressure. Research measuring this pressure shows that heels and the back of the head consistently register some of the highest readings on a standard mattress surface, and that switching to a pressure-redistributing clinical mattress can lower heel pressure by more than 30 percent compared to conventional surfaces.1PubMed. Impact of a new clinical mattress solution on interface pressure and comfort during supine lying
This is the same reason hospital patients who spend long periods on their backs are at elevated risk of developing pressure injuries on the heels. You are unlikely to develop a wound from a single night of sleep, but the underlying physics is the same: a hard bone, thin tissue coverage, and a surface that does not give enough. If you also tend to sleep with your legs straight and feet naturally falling outward, the outermost edge of each heel can dig into the mattress at an even sharper angle, amplifying the discomfort.
Plantar Fasciitis and Resting Pain
Plantar fasciitis is the most common cause of heel pain in general, and it can easily make lying on your back uncomfortable, though the mechanism is a little different from pure pressure. The plantar fascia is a thick band of connective tissue running along the sole of your foot from the heel bone to the toes. When you are off your feet for a while, this tissue contracts and tightens. That is why the classic symptom of plantar fasciitis is a stabbing pain in the heel with your first steps in the morning: the fascia has shortened overnight, and stepping on it forces it to stretch abruptly.
Lying supine can trigger a version of the same process. If your feet are pointed or relaxed, the plantar fascia is in a shortened position. The weight of a blanket pressing your toes downward can shorten it further. When you shift in bed or flex your foot, the tug on the already-irritated attachment point at the heel bone produces pain. Some people also report a dull ache at the heel even without moving, because the inflamed tissue is swollen enough that any contact with the mattress surface irritates it.
If this sounds familiar, one straightforward test is to pull your toes gently upward while lying down. If that stretch reproduces or intensifies the pain along the bottom of the heel, plantar fasciitis is a likely culprit. The condition is common in runners, people who stand for long hours, and those carrying extra body weight.
Insertional Achilles Tendinopathy
The Achilles tendon inserts into the back of the heel bone, and inflammation at this exact spot is called insertional Achilles tendinopathy. It is a separate issue from the more familiar mid-tendon Achilles pain that runners talk about. Insertional tendinopathy produces pain, swelling, and tenderness right where the tendon meets the bone, and it is commonly aggravated by direct pressure, whether from the back of a shoe or from resting the heel against a firm surface.2PubMed Central. Current Concepts Review Update: Insertional Achilles Tendinopathy
When you lie on your back, the posterior heel is the exact point bearing your leg’s weight against the bed. If the Achilles insertion is inflamed or if a bony bump (sometimes called a Haglund deformity) has developed at the back of the heel, even a soft mattress may apply enough pressure to produce real discomfort. The pain tends to be localized to one specific spot, and you can often feel a tender lump or thickened area if you press with your fingers. People with this condition frequently notice that the pain worsens the longer they stay in one position and eases once they elevate the heel or turn onto their side.
Retrocalcaneal bursitis often accompanies insertional tendinopathy. A bursa is a small fluid-filled sac that acts as a cushion between the tendon and the bone, and when it becomes inflamed, it swells and adds to the sensitivity at the back of the heel. The combination of a swollen bursa, a thickened tendon insertion, and the external pressure of a mattress can make supine rest genuinely painful.
Heel Fat Pad Thinning
Under the heel bone sits a specialized pad of fat organized in small chambers separated by fibrous walls. This structure works like a built-in shock absorber, spreading force across the heel during standing and walking. When this fat pad thins out or degrades, the calcaneus loses its cushion, and ordinary pressure that would normally be painless starts to hurt. Fat pad atrophy is frequently underdiagnosed because it mimics plantar fasciitis closely enough that clinicians sometimes miss it.3Techniques in Foot & Ankle Surgery. Heel Pain Reconsidered
Several things accelerate fat pad loss. Aging is the most common factor: the fat pad gradually loses volume and elasticity over time. Obesity and diabetes are also associated with faster deterioration, as are certain rheumatological conditions.4PubMed Central. What do we actually know about a common cause of plantar heel pain? A scoping review of heel fat pad syndrome Repetitive high-impact activity, such as distance running on hard surfaces, can damage the fat pad through chronic overuse as well.4PubMed Central. What do we actually know about a common cause of plantar heel pain? A scoping review of heel fat pad syndrome
The distinguishing feature of fat pad pain versus plantar fasciitis is where exactly the tenderness sits. Plantar fasciitis tends to concentrate at the front-inside edge of the heel, right where the fascia attaches. Fat pad pain is usually more central, directly under the heel bone, and feels bruise-like. When you lie on your back and the heel bone presses into the mattress with nothing but a thinned pad in between, the result can feel like resting your heel on a rock.
Inflammatory Conditions That Target the Heel
Some systemic inflammatory diseases specifically attack the entheses, which are the sites where tendons and ligaments anchor into bone. The heel has two major entheses: the Achilles tendon insertion on the back and the plantar fascia insertion on the bottom. These are prime targets in a family of conditions called spondyloarthritis, which includes ankylosing spondylitis and psoriatic arthritis.
Enthesitis at the heel can be extremely painful and resistant to common treatments like over-the-counter anti-inflammatory drugs. In some cases, the inflammation is severe enough to cause significant disability. Case reports describe patients with calcaneal enthesitis so debilitating that only biologic medications, specifically TNF-alpha inhibitors, provided relief.5Rheumatology. Spectacular improvement of refractory calcaneal enthesitis with anti TNF alpha
If your heel pain at night comes with other symptoms like morning stiffness in your lower back lasting more than 30 minutes, swollen fingers or toes, or skin plaques, it is worth raising the possibility of spondyloarthritis with a doctor. These conditions tend to produce pain that is worst at rest and actually improves with movement, which is the opposite pattern from most mechanical injuries. Lying in bed at night is exactly the scenario where inflammatory heel pain flares, and the mattress pressure on an already-inflamed enthesis makes it worse.
Peripheral Artery Disease and Rest Pain
A less obvious cause of heel pain while lying down is poor blood flow to the feet. Peripheral artery disease, or PAD, occurs when the arteries supplying the legs become narrowed by plaque buildup. In its earlier stages, PAD causes cramping in the calves during walking that goes away with rest. But as the disease progresses, blood flow can become so restricted that the feet hurt even at rest, particularly when lying flat, because gravity is no longer helping push blood downhill into the legs.
This type of rest pain often affects the toes and forefoot, but it can involve the heel as well. A characteristic sign is that dangling the legs over the side of the bed or standing up provides quick relief, because gravity restores some blood flow. People with PAD-related rest pain also commonly notice that their feet are cool to the touch, that minor wounds on their feet heal slowly, or that the skin on their lower legs has become thin and shiny. Risk factors include smoking, diabetes, high blood pressure, and high cholesterol.
If your heel pain at night improves when you sit up or let your feet hang down, and especially if you have any of those risk factors, it is worth getting checked for vascular disease. PAD rest pain is a sign of advanced disease that benefits from early treatment.
How Your Mattress and Sleeping Position Contribute
The surface you sleep on has a direct impact on how much pressure your heels experience. A firm, non-conforming mattress does not distribute your weight evenly, so bony prominences like the heel absorb a disproportionate share of the load. Studies measuring interface pressure have found meaningful differences between mattress types, with pressure-redistribution surfaces significantly lowering the force concentrated on the heels and other bony contact points.1PubMed. Impact of a new clinical mattress solution on interface pressure and comfort during supine lying
You do not need a clinical-grade mattress to make a difference. A few practical adjustments can reduce heel pressure at night:
- Pillow under the calves: Placing a pillow or folded blanket under your lower legs lifts the heels completely off the mattress. This is the simplest and most effective fix for pure pressure-related heel pain.
- Heel suspension boots: These are padded devices, commonly used in hospitals, that cradle the lower leg and keep the heel floating in space. Over-the-counter versions exist for home use.
- Mattress topper: A memory foam or latex topper adds a conforming layer that increases the contact area under the heel, spreading the load and reducing peak pressure.
- Side sleeping: Turning onto your side takes the heel entirely out of the equation, though this is not always comfortable or practical for people with back or hip issues.
For anyone who already has one of the conditions described above, reducing mattress pressure on the heel is a useful complement to treating the underlying problem. It will not fix inflamed tissue or restore a thinned fat pad, but it can make sleep significantly more comfortable while recovery is underway.
Night Splints for Plantar Fasciitis
If plantar fasciitis is the main driver of your nighttime heel pain, a dorsiflexion night splint is one of the better-studied interventions. These splints hold the foot in a gently flexed-upward position while you sleep, preventing the plantar fascia from contracting and tightening overnight. In a randomized crossover trial of patients with chronic plantar fasciitis that had not responded to other treatments, roughly 80 percent of feet improved after just one month of nightly splint wear, and those improvements held for the remaining months of follow-up.6PubMed. Effective treatment of chronic plantar fasciitis with dorsiflexion night splints: a crossover prospective randomized outcome study A separate prospective study found similarly encouraging results, with about three-quarters of patients reporting symptom improvement at one month.7PubMed. A prospective trial of night splinting in the treatment of recalcitrant plantar fasciitis: the Ankle Dorsiflexion Dynasplint
Night splints are not the most comfortable things to sleep in, and compliance matters. In the trials where they worked well, patients wore them for the vast majority of their sleeping hours. But for people who have been dealing with months of stubborn heel pain and dread lying down at night, the tradeoff is often worthwhile. The splints are inexpensive, available without a prescription, and can be combined with the heel-elevation strategies discussed above.
One thing night splints do not address is the direct pressure on the back of the heel. Depending on the splint design, the rigid shell can actually increase pressure on the posterior heel, which is counterproductive if insertional Achilles tendinopathy or a Haglund deformity is part of the picture. If your pain is at the back of the heel rather than the bottom, a splint may not be the right tool, and offloading the heel with a pillow or suspension device is a better first step.
How Nighttime Pain Affects Sleep Quality
Heel pain at rest does not just hurt your feet. It erodes sleep quality, and poor sleep in turn lowers your pain threshold, creating a cycle that feeds on itself. Research on patients with joint conditions has found that the frequency of nocturnal pain is independently associated with poor sleep quality, even after accounting for other factors like pain severity during the day.8Osteoarthritis and Cartilage Open. Nocturnal pain and pain sensitivity–related symptoms are associated with poor sleep quality in patients with hip osteoarthritis Patients with more frequent nighttime pain episodes also showed higher scores on measures of central sensitization, meaning their nervous systems were amplifying pain signals in general.
This has practical implications. If your heel pain wakes you up or prevents you from falling asleep, addressing it is not just about foot comfort; it is about protecting your overall sleep architecture. Even a partial solution, like repositioning your legs so the heels float free of the mattress, may reduce wake-ups enough to meaningfully improve how rested you feel. And better sleep may, over time, reduce how sensitive your heels are to pressure in the first place.
When to See a Doctor
Most supine heel pain comes from benign, treatable causes, and the self-care strategies above handle the majority of cases. But certain patterns warrant professional evaluation sooner rather than later. Pain that is worse at rest and improves with movement, especially if paired with lower back stiffness, could point to an inflammatory condition like spondyloarthritis that benefits from specific treatment. Heel pain combined with cool feet, slow-healing wounds, or pain relief from dangling the legs suggests a vascular problem that should not wait. And heel pain that persists despite weeks of offloading and splinting deserves imaging to rule out a stress fracture of the calcaneus or other structural issues that self-care will not resolve.
For everyone else, the fix is often mechanical. Thin heels on a hard surface hurt. Giving them a softer landing, or better yet, suspending them off the surface entirely, removes the trigger. Combining that with treatment for any underlying fascia, tendon, or fat pad problem addresses the sensitivity that made ordinary mattress contact painful in the first place.