Fat pads are specialized cushions of fatty tissue found throughout your body, positioned in areas where bones, joints, and soft tissues need protection from pressure and friction. Unlike the general layer of fat beneath your skin that stores energy, fat pads serve a structural role: they act as shock absorbers, fill dead space inside joints, and protect delicate structures like nerves and blood vessels. You have fat pads in your knees, heels, eye sockets, face, and several other locations, each shaped and sized for its specific job.
How Fat Pads Differ From Body Fat
The fat you might think of when you hear the word “fat” is subcutaneous fat, the energy-storing layer spread beneath your skin. Fat pads are different. They’re dense, highly organized cushions anchored in precise locations. Their primary job isn’t energy storage but mechanical support. In joints like the knee, fat pads are enclosed within the joint capsule itself, where they dynamically change shape as the joint moves to fill gaps between bones, tendons, and ligaments.
Beyond cushioning, fat pads contribute to functions you might not expect. Knee fat pads help regulate local inflammation, secrete compounds that influence surrounding tissues, and contain nerve endings that provide pain feedback. They’re active participants in joint health, not just passive padding.
Fat Pads in the Knee
The knee contains several fat pads, the largest and most well-known being the infrapatellar fat pad, sometimes called Hoffa’s fat pad. It sits just below the kneecap, between the patellar tendon and the thighbone. During movement, it deforms and reshapes itself to fill the shifting space between these structures, reducing friction with each bend and straightening of the knee.
The infrapatellar fat pad also helps stabilize the kneecap at the extremes of motion, particularly when the knee is nearly straight (less than 20 degrees of bend) or deeply flexed (beyond 100 degrees). Other fat pads in the knee sit behind the kneecap and near the back of the joint, each accommodating different structures as the knee moves. The posterior fat pad, for example, reduces friction between the cruciate ligaments deep inside the joint.
Hoffa’s Syndrome
When the infrapatellar fat pad becomes inflamed, it can swell and get pinched between the thighbone and shinbone. This is called Hoffa’s syndrome, or fat pad impingement, and it’s a recognized cause of pain at the front of the knee. The trapped fat pad swells further, creating a cycle of inflammation and repeated impingement. Over time, the tissue can develop fibrous scarring that limits knee motion and causes lingering pain. The surrounding thigh muscles can weaken as a result.
Diagnosis usually involves a physical exam where pressure is applied alongside the kneecap while the knee is bent to about 45 degrees. Pain during this test is a positive sign. MRI can support the diagnosis but isn’t reliable on its own. In some cases, a numbing injection into the joint is used: if the pain disappears, the fat pad is likely the source.
Fat Pads in Your Heels
The heel fat pad is a thick cushion of fatty tissue directly beneath the heel bone. A healthy heel pad measures 1 to 2 centimeters thick and absorbs the repeated impact of walking, running, and jumping. Every step you take sends a force of up to twice your body weight through your heel, and this fat pad distributes that load so the bone and surrounding tissues aren’t damaged.
When the heel fat pad thins or breaks down, a condition called heel fat pad syndrome, you lose that natural shock absorption. The result is a deep, bruise-like ache directly under the heel that worsens with standing and walking, especially on hard surfaces. Aging is the most common cause, as the fat pad gradually loses its elasticity and volume over decades. Repeated high-impact activity and wearing flat, unsupportive shoes can accelerate the process.
Fat Pads in Your Face
Your face contains multiple distinct fat compartments, both deep and superficial, that give it shape and fullness. In youth, this fat is evenly distributed, plumping the forehead, temples, cheeks, and the areas around the eyes and mouth. These fat pads are a major reason young faces look smooth and rounded.
With age, facial fat pads lose volume, clump together, and shift downward. Areas that were formerly full, like the temples and mid-cheeks, begin to hollow. Skin that sat over plump fat pads becomes loose and sags. At the same time, fat tends to accumulate in the lower face, contributing to fullness around the chin and neck. This redistribution, not just skin loosening, is one of the biggest drivers of an aging appearance.
The buccal fat pad, located in each cheek, has become a target for cosmetic surgery. People who feel their cheeks appear too full or lack definition sometimes opt to have these fat pads partially removed to create a more sculpted look. This is typically done as a relatively minor outpatient procedure.
Fat Pads Around the Eyes
Inside each eye socket, fat pads surround and cushion the eyeball, protecting the blood vessels and nerves that connect the eye to the brain. This orbital fat sits both inside and around the cone of muscles that control eye movement.
The tissue wall (called the orbital septum) that holds this fat in place can weaken over time. When it does, the fat pushes forward, creating the puffy bags under the eyes that many people associate with aging or fatigue. This herniation of orbital fat is the structural cause of under-eye bags, distinct from temporary puffiness caused by fluid retention.
Managing Fat Pad Problems
Treatment for fat pad issues depends on the location and severity. For knee fat pad impingement, the initial approach focuses on reducing inflammation: ice massage, anti-inflammatory medications, and a specific taping technique called McConnell taping that lifts pressure off the irritated fat pad. Flat shoes should be avoided during flare-ups because they increase loading on the infrapatellar fat pad. Slightly elevated heels can help correct patterns of knee hyperextension that contribute to impingement.
Longer-term management includes exercises to strengthen the quadriceps and stretch the front of the hip, both of which reduce abnormal stress on the fat pad. Weight management plays a meaningful role as well. An 18-month clinical trial found that a combined exercise and diet program significantly reduced infrapatellar fat pad volume by lowering overall body fat percentage.
For heel fat pad thinning, cushioned insoles and supportive footwear are the main tools. There’s no way to rebuild the fat pad once it’s lost, so the goal is to replace its shock-absorbing function externally. In the face and around the eyes, cosmetic procedures like injectable fillers or surgical repositioning can address fat pad changes, but these are appearance-driven choices rather than medical necessities.