Within the infinite list of known rare diseases, there are some as mysterious for the scientific community as Sudeck’s syndrome, whose first record dates from 1864 .

Throughout this article we will describe what this strange syndrome consists of, which causes immense pain in those who appear to be in it. We will also discuss its symptoms, possible causes, and treatment.

What is Sudeck’s syndrome?

Sudeck’s disease, also known as complex general pain syndrome (CPS), is a disease characterized by being quite painful affecting one or more body extremities.

This condition tends to originate after some type of injury or operation, and is distinguished by being a syndrome, multi-symptomatic and multi-systemic. The degree of pain and the evolution of Sudeck’s syndrome does not necessarily correspond to the magnitude of the injury that triggers it.

It is vital that this rare syndrome be diagnosed at the earliest possible stage. Otherwise, may end up spreading to all the extremities , making your recovery much more painful and difficult.

Given the high levels of pain caused by this disease, the person may manifest serious psychological alterations, pharmacological dependence or even develop complete disability.

Another factor that makes this disease so disabling for the person who suffers it is that its course is totally unpredictable and can vary exaggeratedly from one person to another.

Symptomatology and clinical picture

As mentioned above, Sudeck’s disease has a wide variety of clinical features. These symptoms include pain or changes in the skin and bones. Below we describe each of these clinical symptoms:

1. Pain

This syndrome has the singularity that the person experiences a pain of disproportionate proportions compared to the magnitude of the injury or damage that causes it.

In addition, it may be accompanied by mobility difficulties that appear after the injury. One of the first symptoms to appear in Sudeck syndrome patients is severe, constant, deep, burning pain.

Finally, any kind of rubbing, no matter how intense, is experienced as a painful sensation of the highest level.

2. Skin alterations

The dermis may show symptoms of dystrophy or atrophy, as well as dryness with or without scaling. The abnormal sympathetic activity that causes this disease may be related to alterations in skin pigmentation, skin temperature and sweating levels .

3. Bone alterations

Sudeck’s syndrome can lead to bone wasting or osteoporosis in the joints. This wear and tear can be seen by x-rays and scans of the bones.

4. Motor disorders

People affected by this disease experience great difficulties in making any kind of movement . These difficulties are caused by the intense pain they experience due to the increased muscle tone.

As a consequence, patients tend to decrease their movements, thus generating a diffuse muscular atrophy. Other motor symptoms are tremors or involuntary reflex movements.

5. Inflammation

In most cases, patients have localized inflammation where the pain is generated.

All of these symptoms tend to be located at the site of the injury. However, as the disease evolves, all these symptoms will start to spread. There are 3 patterns that describe the spread of the disease:

  • Continuous pattern: symptoms spread upwards . For example, from the wrist to the shoulder.
  • Mirror image type pattern: propagation to the opposite end .
  • Independent type pattern: in this case the symptoms extend to a distant area of the body .

Causes and risk factors

The causes of Sudeck’s disease are as yet unknown. Therefore, it is not yet understood why the sympathetic system is constantly kept in a hyperactive mode .

Some theories hypothesize that this hyperactivity triggers an inflammatory response that causes constant spasms at the site of injury. These spasms may also cause the pain to increase, becoming a continuous cycle of discomfort.

Although the causes are unknown, there are a number of risk factors associated with Sudeck’s syndrome . These are:

  • Previous surgeries
  • Infections.
  • Spinal conditions .
  • .

  • Idiopathic disorders.
  • Neurological lesions both central and peripheral.
  • Cardiovascular diseases.
  • Previous trauma , repetitive strain or repetitive motion disorders.


Since there are no specific diagnostic tests for Sudeck syndrome, a differential diagnosis is necessary to rule out any other disorder with similar symptoms.

As a result, the diagnosis will be made mainly by observing signs and symptoms. Some of the tests that can be performed to try to diagnose this disease are

1. X-rays

Using x-rays, a class of spotted osteoporosis characteristic of this syndrome can be identified.

2. Nuclear magnetic resonance

This is a useful test for early detection of Sudeck syndrome, especially when the injury is located at hip level.

3. Thermography

Thermography is a test in which by using a specialized camera you can measure the heat emitted by the body .

4. Laboratory analysis

Blood and urine tests will evaluate the presence of hypertriglyceridemia, hyperuricemia, hypercalciuria and hydroxyprolinuria .


The most important goal in the treatment of Sudeck syndrome is to get the patient to use the affected limb .

By using medication, physical therapy or nerve blocks, the aim is to make the pain less severe. In addition, the physical therapy intervention will teach the patient how to use their affected limb in their day-to-day activities.

Physical exercises such as swimming or any other water activity, have been shown to be highly effective in patients affected by lower extremities.

Psychological accompaniment is of vital importance in the treatment of Sudeck’s syndrome. Its objective is to reinforce the mental or psychological aspects of the disease , as well as to motivate the patient to carry out pain management techniques.

If this treatment is successful in the early stages of the disease, the probability of complete remission is approximately 85% . In cases where the disease does not receive adequate treatment, it can lead to becoming chronic.