Buffalo Hump (Neck Hump): Weight, Cushing's or Posture, and Does Weight Loss Shrink It?

A buffalo hump, also called a neck hump, is a soft pad of fat that builds up over the base of the neck and the top of the back. Doctors call it a dorsocervical fat pad. It is famous as a sign of Cushing's syndrome, but it is far more often a feature of ordinary weight gain: in a Turkish study of 354 people attending an obesity clinic, 72% had one, while only 2 turned out to have Cushing's syndrome ^[1]. This review covers what causes it, how it differs from a “dowager's hump” caused by the spine, which other signs make a cortisol test worth doing, and what the evidence says about weight loss, GLP-1 drugs and liposuction.

The honest summary

• Most buffalo humps come with excess weight, not disease. 72% of people in one obesity clinic had a dorsocervical fat pad ^[1], and in a large surgical series only 1 of 383 patients had HIV ^[3].
• A hump on its own is a weak sign of Cushing's syndrome. Of 354 people with obesity screened, 2 had it ^[1]. Wide purple stretch marks, easy bruising, a flushed face, thigh-muscle weakness and unexplained bone thinning point to it more strongly ^[6].
• A dowager's hump is a different thing. It is a forward curve of the upper spine (hyperkyphosis), common in older adults, and is treated with exercise and bone care rather than weight loss ^[11][12].
• HIV-associated humps are usually not a cortisol problem. In a 1998 study, eight men with HIV and a hump all had normal cortisol suppression ^[8].
• No study has tested whether weight loss or GLP-1 drugs shrink it. Treating Cushing's disease reduces trunk fat ^[9], but that is a different situation from ordinary weight loss.
• Liposuction works in most reported cases. Pooled recurrence was about 1 in 10, from low-quality evidence ^[10].

What a buffalo hump is, and what it is not

A buffalo hump is fat. It sits in the soft tissue over the lowest neck bones and the top of the spine, and it feels soft or rubbery when pressed. Surgeons who operated on 383 people with one in China sorted the humps into four types on appearance and MRI: a defined fat pad (78%), a more diffuse fat build-up (11%), a fatty lump called a nuchodorsal lipoma (10%), and mixed forms (1%) ^[3]. A lipoma is a benign fat growth and is handled differently from general fat build-up, which is one reason a new or growing lump is worth having examined.

A dowager's hump is bone, not fat. It is an exaggerated forward curve of the upper back, called hyperkyphosis, which makes the head and shoulders sit forward. Estimates put it at 20% to 40% of older adults ^[11]. It is often blamed on spinal fractures from osteoporosis, but many of the people most affected have no vertebral fracture at all ^[11]. The two can coexist: a forward-curved spine can make a fat pad look larger, and a fat pad can make a mild curve look worse. A clinician can usually tell them apart by examination, and an X-ray settles it if needed.

What causes a buffalo hump?

Excess weight and metabolic health

The most common setting is general weight gain. In the Turkish obesity-clinic study, the average BMI was 40 and 72% of the 354 patients had a dorsocervical fat pad ^[1]. Among surgical patients, HIV is now the exception: only 1 of the 383 people in the Chinese series was HIV-positive ^[3].

A small Korean study suggests the hump can travel with metabolic disease. Twelve HIV-negative patients who had theirs removed had an average BMI of 30.2; two-thirds had high blood pressure, two-thirds had diabetes and three-quarters had high cholesterol, and three of them were newly diagnosed with a metabolic condition during their workup ^[2]. The authors were clear that 12 patients cannot settle the question, but they suggested checking blood pressure, blood sugar and lipids in anyone who presents with a hump.

Cushing's syndrome and steroid medicines

Cushing's syndrome is long-term excess of the stress hormone cortisol. It redistributes fat into the cheeks (“moon face”), the neck, the hollows above the collarbones and the upper back, which is where the buffalo hump gets its fame ^[6]. Steroid medicine such as prednisone can produce the same picture, which is why the Endocrine Society guideline says to rule out glucocorticoid use before testing for the syndrome ^[4]. For how steroid treatment interacts with weight-loss drugs, see GLP-1 drugs and prednisone. The condition itself, including its pituitary form, is covered in GLP-1 drugs in acromegaly and Cushing's.

HIV and antiretroviral treatment

Buffalo humps became widely known in the late 1990s in people treated for HIV. A 1998 study of eight men with HIV who developed a hump found that none had Cushing's syndrome: all suppressed cortisol normally on a dexamethasone test, and only four were taking the protease inhibitors that had been blamed ^[8]. The men did carry a larger share of their fat in the trunk than matched HIV-positive controls. There is one important exception. The HIV booster ritonavir slows the breakdown of fluticasone, a steroid in some asthma inhalers and nasal sprays, and a review found 25 cases of significant adrenal suppression with inhaled fluticasone and 3 with the nasal form, some with Cushing's features ^[13]. The reviewers stressed that this steroid-driven form needs to be told apart from antiretroviral fat changes. HIV-related fat changes and modern regimens are covered in weight gain on HIV integrase inhibitors.

Lipodystrophy: the lookalike

Partial lipodystrophy, a group of conditions in which fat is lost in some areas and gained in others, can look strikingly like Cushing's syndrome. An Italian study compared 61 people with partial lipodystrophy and 56 with Cushing's syndrome ^[7]. A dorsocervical fat pad was more common in the lipodystrophy group, as were a full face and excess hair, and those patients scored as high or higher on clinical Cushing's checklists. What separated the groups was proximal muscle wasting and osteoporosis, which pointed to Cushing's, and diabetes with high triglycerides, which pointed to lipodystrophy.

Is a buffalo hump a sign of Cushing's syndrome?

Sometimes, but rarely on its own. Cushing's syndrome shares many features with ordinary obesity, so the hump has to be read alongside other signs. The most useful are the ones caused by the protein breakdown that excess cortisol drives: wide purple stretch marks, a flushed face, weakness in the thigh and shoulder muscles, easy bruising without a cause, and bone thinning without another explanation ^[6].

The hump is not useless in the right setting. A Spanish study screened 353 higher-risk patients attending endocrinology clinics and found 26 cases ^[5]. Its best scoring model combined muscle wasting, osteoporosis, a dorsocervical fat pad and a late-night saliva cortisol test, with a sensitivity of 96% and a specificity of 83%. In other words, the hump adds information when other signs are present, but in someone whose only finding is a hump alongside general weight gain, the odds of Cushing's are low.

How testing works

The Endocrine Society recommends testing people who have several features that are getting worse over time, particularly the more specific ones above, after any steroid medicine has been ruled out ^[4]. The first test is one of a 24-hour urine cortisol, a late-night saliva cortisol or an overnight dexamethasone suppression test, and an abnormal result is followed by a second test with an endocrinologist ^[4]. Routine cortisol testing of everyone with obesity is not recommended: in the Turkish clinic, 7 of 354 patients failed the first test but only 2 were confirmed to have the condition ^[1]. Stress and cortisol in everyday life are a separate topic, covered in cortisol, stress and belly fat.

Does losing weight shrink a buffalo hump?

No study has measured it. No published trial or cohort has tracked the dorsocervical fat pad during dieting, bariatric surgery or GLP-1 treatment. What can be said is indirect. The hump is very common in obesity ^[1], so it is reasonable to expect it to shrink with general fat loss, as other fat stores do. Surgeons also describe some humps as fibrous rather than purely fatty ^[10], and a lipoma is a discrete growth rather than general fat ^[3]; those are less likely to respond to weight loss alone.

When the cause is Cushing's disease, treating it helps. A prospective MRI study followed 14 patients from active disease to remission after surgery and found that visceral fat, fat under the skin of the trunk and limbs, waist size and weight all fell ^[9]. Muscle mass also fell, and the study did not measure the neck pad specifically.

What about GLP-1 drugs?

There is no study of semaglutide, tirzepatide or any other GLP-1 drug and the buffalo hump. These drugs reduce overall body fat, so a smaller hump would be an expected side benefit for someone whose hump comes from general weight gain, but that is untested. A GLP-1 drug does not treat Cushing's syndrome, and weight loss on one should not delay testing if the warning signs above are present. Stress-related eating and cortisol are covered in stress, cortisol and food noise.

Liposuction and surgery

For a hump that persists and bothers someone, removal is the most studied option. A 2026 meta-analysis pooled 22 studies with 218 patients, most of whom had HIV-related humps ^[10]. Suction lipectomy (liposuction) was the most common technique, with a pooled recurrence rate of 10.6% and revision procedures in 15.3%. In a sensitivity analysis, both rates fell to about 1%. Cutting the fat out (excision), alone or combined with liposuction, had no recurrences but more wound problems. Complications included fluid collections, bleeding and wound breakdown. The authors rated the overall evidence as low quality.

The largest single series, 383 mostly HIV-negative patients, reported no recurrences ^[3]. Complications were skin numbness in 14%, a fluid collection (seroma) in 6%, a raised scar in 2% and bleeding under the skin (hematoma) in under 1%. Neither report compared surgery with no treatment or with weight loss, and if the underlying cause continues, the fat can return.

Posture, exercise and the dowager's hump

Exercise cannot remove a fat pad, but it can improve a forward-curved upper back. A 2021 meta-analysis of 24 studies in adults aged 45 and older with marked curvature (an average of at least 40 degrees in at least one group) found that exercise or physical therapy improved the curve, with moderate certainty (standardized mean difference −0.31) ^[12]. Quality of life also improved with moderate certainty, and back-muscle strength and pain improved with lower certainty. Hyperkyphosis may be linked with poorer lung function, reduced physical function and future fractures ^[11], so it is worth checking bone density as well; see GLP-1 drugs and osteoporosis.

Practical guidance

• Work out which hump you have. Soft tissue over the base of the neck is fat; a rounded, stiff upper back with the head pushed forward is the spine.
• List every steroid you use, including inhalers and nasal sprays, and any HIV medicine. Steroid use has to be ruled out before cortisol testing ^[4], and some HIV boosters strengthen inhaled steroids ^[13].
• Look for the stronger warning signs. Wide purple stretch marks, bruising, thigh weakness, a flushed face or unexplained fractures justify testing ^[6].
• Check blood pressure, blood sugar and cholesterol. A hump may be a visible marker of metabolic risk ^[2].
• Expect weight loss to help a fatty hump, without a guarantee. It has never been measured.
• For a spine curve, start with exercise. Strengthening and posture work has moderate-certainty evidence ^[12].
• Consider surgery only for a persistent hump, after the cause has been looked at, and ask about numbness and seroma risk ^[3].