The prevalence of adiposis dolorosa is unknown. However, it affects women more frequently than men. Most commonly, it appears in overweight women between the ages of 35-50. Rarely, children have been affected.

The cause of adiposis dolorosa is not known. There are many hypotheses proposed but none have been confirmed. These hypotheses include dysfunction in the nervous system, the endocrine system which is responsible for hormone production to regulate body functions, trauma, and abnormal metabolism of fat. 

Some suggest that adiposis dolorosa may be an autoimmune disorder where the immune system redundantly attacks healthy tissue. However, autoimmune disorders are expected to cause inflammation above normal levels. Inflammation is an immune response that can cause tissue damage if it persists. In individuals affected by adiposis dolorosa, inflammation appears to be similar to otherwise healthy, obese individuals. This provides evidence against the autoimmunity hypothesis. In some cases, the use of high dosages of a class of drugs called corticosteroids has been associated with adiposis dolorosa. Corticosteroids are anti-inflammatory drugs that reduce the symptoms associated with inflammation. 

There is some evidence suggesting that there is a genetic link. For example, there are families with more than one case of this disorder. In those cases, adiposis dolorosa appears to be autosomal dominant. An autosomal dominant disorder is a disorder that is caused by the presence of one defective gene. Each person inherits two copies of genes, one from each parent. While in some cases, if one copy of a gene is defective, the other copy can compensate. In other cases, the presence of one defective copy is enough to cause dysfunction. This is known as an autosomal dominant mode of inheritance. Despite this evidence, most cases of adiposis dolorosa are not inherited, and no specific genes have been identified.

The pain associated with the fatty nodules is also not understood. It is possible that these fatty growths press on nearby nerves and cause pain and weakness.

Adiposis dolorosa can be classified into four subtypes. The generalized diffuse type is characterized by general pain in fatty tissue around the body without any apparent lipomas. In the generalized nodular type, fatty tissue is generally painful and lipomas are present. Pain in the fatty tissue is more pronounced around the lipomas. In the localized nodular type, pain is localized to the lipomas. In the juxta-articular types, fatty tissue is painful near large joints.

The most common initial symptom is the growth of painful nodules that are sensitive to touch. The quality of this pain is described as burning, stabbing, and aching. These nodules vary in size from small to large.

Other symptoms include swelling, especially in the hands, and sudden, unexplained weight gain.  Generalized fatigue and weakness, bruising easily, headaches, irritability, sleep disturbances, depression, memory and concentration problems, flushing, shortness of breath, rapid heart rate, and gastrointestinal problems are among other symptoms. 

Them diagnosis of adiposis dolorosa is clinical and based on the presence of generalized obesity and chronic, painful fatty tissue just below the skin or multiple painful fatty nodules. The presence of other associated symptoms can help with diagnostic certainty. 

While adiposis dolorosa is primarily diagnosed based on symptoms, a biopsy of the fatty nodules can be helpful. During a biopsy, a small piece of the painful tissue is removed and examined to confirm that it is a lipoma. 

Although not common, ultrasound and magnetic resonance imaging (MRI) have been used as diagnostic tests. Ultrasound and MRI can visualize multiple fatty nodules under the skin if they are present. 

The goal of the management of adiposis dolorosa is pain reduction. Although none of the currently available treatments have successfully led to permanent pain relief, some treatments have temporarily reduced pain. Liposuction and surgical removal of painful lipomas has been helpful in some cases. However, lipomas may recur or pain reduction effects of these treatments decrease over time. Traditional pain medications can also provide some pain relief. Recently, transcutaneous frequency rhythmic electrical modulation system (FREMS) has been effective for pain reduction. In FREMS, electrodes are placed on the skin and send electrical signals to the nerves and interact with live tissue and can lead to pain reduction.

In individuals with joint pain, weight reduction can alleviate their pain, but weight reduction generally is not an effective treatment. Medications that increase the amount of water that is excreted through urination (diuretics) can reduce swelling of the hands and fingers. 

Adiposis dolorosa is a chronic disease and tends to progress and worsen over time. The associated pain is difficult to manage and usually does not respond well to treatment. 

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