Diagnosis is largely based on patient description and relevant details about recent surgeries, hip injuries, or repetitive activities that could irritate the nerve. Examination checks for sensory differences between the affected leg and the other leg. Accurate diagnosis may require an abdominal and pelvic examination to exclude problems in those areas.

Electromyographic (EMG) nerve-conduction studies may be required. X-rays may be needed to exclude bone abnormalities that might put pressure on the nerve; likewise CT or MRI scans to exclude soft tissue causes such as a tumor.

Treatment varies. In most cases, the best treatment is to remove the cause of compression by modifying patient behavior, in combination with medical treatment to relieve inflammation and pain. Whatever the cause, typical treatment takes several weeks to months—depending on the degree of nerve damage. Typical treatment options include:

- Active Release Technique (ART) soft tissue treatment

- Wearing looser clothing and suspenders rather than belts

- Weight loss if obesity is present

- Non-steroidal anti-inflammatory drugs (NSAIDs) to reduce inflammatory pain if pain level limits motion and prevents sleep

- Reducing physical activity in relation to pain level. Acute pain may require absolute bed rest

- Deep tissue massage to reduce tension in the gluteal muscles, most commonly the gluteus maximus. The tensor fasciae latae may also be implicated.

The lateral cutaneous nerve of the thigh can occasionally be damaged during laparoscopic hernia repair, or scarring from the operation can lead to meralgia paraesthetica.

For lower pain levels, treatment may involve having the patient:

- Seek appropriate physical therapy, such as stretching and massage, which plays a large role in the management of pain

- Learn to perform inguinal ligament stretching (from a physical therapist or from a YouTube video) which can rapidly relieve symptoms

- Use rest periods to interrupt long periods of standing, walking, cycling, or other aggravating activity

- Lose weight, and exercise to strengthen abdominal muscles

- Wear clothing that is loose at the upper front hip area

- Apply heat, ice, or electrical stimulation

- Take nonsteroidal anti-inflammatory medications for 7–10 days

- Remove hair in affected area (shave)

- Lidocaine patches (must shave area first)

- Titanium dioxide patches to interfere with the electrostatic effect of the nerves on the surface of the skin

Pain may take significant time (weeks) to stop and, in some cases, numbness persists despite treatment. In severe cases, the physician might perform a local nerve block at the inguinal ligament, using a combination of local anaesthetic (lidocaine) and corticosteroids to provide relief that may last several weeks. Pain modifier drugs for neuralgic pain (such as amitriptyline, carbamazepine or gabapentin) may be tried, but are often not as helpful in the majority of patients.

Persistent and severe cases may require surgery to decompress the nerve or, as a last resort, to resect the nerve. The latter treatment leaves permanent numbness in the area.

The nerve conduction study usually provides useful information for making diagnosis. A CT scan is sometimes used to rule out some causes from the central nervous system.

Medications offered can include the immunosuppressant prednisone, intravenous gamma globulin (IVIG), anticonvulsants such as gabapentin or Gabitril and antiviral medication, depending on the underlying cause..

In addition to treatment of the underlying disorder, palliative care can include the use of topical numbing creams, such as lidocaine or prilocaine. Care must be taken to apply only the necessary amount, as excess can contribute to the condition. Otherwise, these products offer extremely effective, but short-lasting, relief from the condition.

Paresthesia caused by stroke may receive some temporary benefit from high doses of Baclofen multiple times a day. HIV patients who self-medicate with cannabis report that it reduces their symptoms.

Paresthesia caused by shingles is treated with appropriate antiviral medication.

Diagnosis of Harlequin syndrome is made when the individual has consistent signs and symptoms of the condition, therefore, it is made by clinical observation. In addition, a neurologist or primary care physician may require an MRI test to rule out similar disorders such as Horner's syndrome, Adie's syndrome, and Ross' syndrome. In an MRI, a radiologist may observe areas near brain or spinal cord for lesions, or any damage to the nerve endings. It is also important that the clinician rules out traumatic causes by performing autonomic function tests. Such tests includes the following: tilt table test, orthostatic blood pressure measurement, head-up test, valsalva maneuver, thermoregulatory sweat test, tendon reflex test, and electrocardiography (ECG). CT scan of the heart and lungs may also be performed to rule out a structural underlying lesion. The medical history of the individual should be carefully noted.

One possible cause of Harlequin syndrome is a lesion to the preganglionic or postganglionic cervical sympathetic fibers and parasympathetic neurons of the ciliary ganglion. It is also believed that torsion (twisting) of the thoracic spine can cause blockage of the anterior radicular artery leading to Harlequin syndrome. The sympathetic deficit on the denervated side causes the flushing of the opposite side to appear more pronounced. It is unclear whether or not the response of the undamaged side was normal or excessive, but it is believed that it could be a result of the body attempting to compensate for the damaged side and maintain homeostasis.

Since the cause and mechanism of Harlequin syndrome is still unknown, there is no way to prevent this syndrome.

If a contracture is less than 30 degrees, it may not interfere with normal functioning. The common treatment is splinting and occupational therapy. Surgery is the last option for most cases as the result may not be satisfactory.

There is considerable research into the causes, diagnosis and treatments for FGIDs. Diet, microbiome, genetics, neuromuscular function and immunological response all interact. Heightened mast cell activation has been proposed to be a common factor among FGIDs, contributing to visceral hypersensitivity as well as epithelial, neuromuscular, and motility dysfunction.

Diagnosis involves consideration of physical features and genetic testing. Presence of split uvula is a differentiating characteristic from Marfan Syndrome, as well as the severity of the heart defects. Loeys-Dietz Syndrome patients have more severe heart involvement and it is advised that they be treated for enlarged aorta earlier due to the increased risk of early rupture in Loeys-Dietz patients. Because different people express different combinations of symptoms and the syndrome was identified in 2005, many doctors may not be aware of its existence, although clinical guidelines were released in 2014-2015. Dr. Harold Dietz, Dr. Bart Loeys, and Dr. Kenneth Zahka are considered experts in this condition.

In the United States, sarcoidosis has a prevalence of approximately 10 cases per 100,000 whites and 36 cases per 100,000 blacks. Heerfordt syndrome is present in 4.1–5.6% of those with sarcoidosis.

In general, children with a small isolated nevus and a normal physical exam do not need further testing; treatment may include potential surgical removal of the nevus. If syndrome issues are suspected, neurological, ocular, and skeletal exams are important. Laboratory investigations may include serum and urine calcium and phosphate, and possibly liver and renal function tests. The choice of imaging studies depends on the suspected abnormalities and might include skeletal survey, CT scan of the head, MRI, and/or EEG.

Depending on the systems involved, an individual with Schimmelpenning syndrome may need to see an interdisciplinary team of specialists: dermatologist, neurologist, ophthalmologist, orthopedic surgeon, oral surgeon, plastic surgeon, psychologist.

Camptodactyly is a medical condition that causes one or more fingers to be permanently bent. It involves fixed flexion deformity of the proximal interphalangeal joints. The fifth finger is always affected.

Camptodactyly can be caused by a genetic disorder. In that case, it is an autosomal dominant trait that is known for its incomplete genetic expressivity. This means that when a person has the genes for it, the condition may appear in both hands, one, or neither. A linkage scan proposed that the chromosomal locus of camptodactyly was 3q11.2-q13.12.

In patients that have already been diagnosed with sarcoidosis, Heerfordt syndrome can be inferred from the major symptoms of the syndrome, which include parotitis, fever, and facial nerve palsy. In cases of parotitis, ultrasound-guided biopsy is used to exclude the possibility of lymphoma. There are many possible causes of facial nerve palsy, including Lyme disease, HIV, Melkersson–Rosenthal syndrome, schwannoma, and Bell's palsy. Heerfordt syndrome exhibits spontaneous remission. Treatments for sarcoidosis include corticosteroids and immunosuppressive drugs.

Diagnosis is made based on features as well as by the very early onset of serious eye and ear disease. Because Marshall syndrome is an autosomal dominant hereditary disease, physicians can also note the characteristic appearance of the biological parent of the child. There are no tests for Stickler syndrome or Marshall syndrome. Some families with Stickler syndrome have been shown to have mutations in the Type II collagen gene on chromosome 1. However, other families do not show the linkage to the collagen gene. It is an area of active research, also the genetic testing being expensive supports that the diagnosis is made depending on the features.

Café au lait spots can be removed with lasers. Results are variable as the spots are often not completely removed or can come back after treatment. Often, a test spot is treated first to help predict the likelihood of treatment success.

As there is no known cure, Loeys–Dietz syndrome is a lifelong condition. Due to the high risk of death from aortic aneurysm rupture, patients should be followed closely to monitor aneurysm formation, which can then be corrected with interventional radiology or vascular surgery.

Previous research in laboratory mice has suggested that the angiotensin II receptor antagonist losartan, which appears to block TGF-beta activity, can slow or halt the formation of aortic aneurysms in Marfan syndrome. A large clinical trial sponsored by the National Institutes of Health is currently underway to explore the use of losartan to prevent aneurysms in Marfan syndrome patients. Both Marfan syndrome and Loeys–Dietz syndrome are associated with increased TGF-beta signaling in the vessel wall. Therefore, losartan also holds promise for the treatment of Loeys–Dietz syndrome. In those patients in which losartan is not halting the growth of the aorta, irbesartan has been shown to work and is currently also being studied and prescribed for some patients with this condition.

If an increased heart rate is present, atenolol is sometimes prescribed to reduce the heart rate to prevent any extra pressure on the tissue of the aorta. Likewise, strenuous physical activity is discouraged in patients, especially weight lifting and contact sports.

In terms of diagnosing Bannayan–Riley–Ruvalcaba syndrome there is no current method outside the physical characteristics that may be present as signs/symptoms. There are, however, multiple molecular genetics tests (and cytogenetic test) to determine Bannayan–Riley–Ruvalcaba syndrome.

Functional gastrointestinal disorders are very common. Globally, irritable bowel syndrome and functional dyspepsia alone may affect 16–26% of the population.

Diagnosis is visual with measurement of spot size. The number of spots can have clinical significance for diagnosis of associated disorders such as Neurofibromatosis type I. Greater than or equal to 6 spots of at least 5mm in diameter in pre-pubertal children and at least 15mm in post-pubertal individuals is one of the major diagnostic criteria for NF1.

Diagnosis can be made by EEG. In case of epileptic spasms, EEG shows typical patterns.

Carrier testing for Roberts syndrome requires prior identification of the disease-causing mutation in the family. Carriers for the disorder are heterozygotes due to the autosomal recessive nature of the disease. Carriers are also not at risk for contracting Roberts syndrome themselves. A prenatal diagnosis of Roberts syndrome requires an ultrasound examination paired with cytogenetic testing or prior identification of the disease-causing ESCO2 mutations in the family.

There is no medical treatment for either syndrome but there are some recommendations that can help with prevention or early identification of some of the problems. Children with either syndrome should have their hearing tested, and adults should be aware that the hearing loss may not develop until the adult years. Yearly visits to an ophthalmologist or other eye care professional who has been informed of the diagnosis of Stickler or Marshall syndrome is important for all affected individuals. Children should have the opportunity to have myopia corrected as early as possible, and treatment for cataracts or detached retinas may be more effective with early identification. Support for the joints is especially important during sports, and some recommend that contact sports should be avoided by those who have very loose joints.

In terms of the diagnosis of Romano–Ward syndrome the following is done to ascertain the condition(the "Schwartz Score" helps in so doing):

- Exercise test

- ECG

- Family history

Many professionals that are likely to be involved in the treatment of those with Stickler's syndrome, include anesthesiologists, oral and maxillofacial surgeons; craniofacial surgeons; ear, nose, and throat specialists, ophthalmologists, optometrists, audiologists, speech pathologists, physical therapists and rheumatologists.

Cytogenetic preparations that have been stained by either Giemsa or C-banding techniques will show two characteristic chromosomal abnormalities. The first chromosomal abnormality is called premature centromere separation (PCS) and is the most likely pathogenic mechanism for Roberts syndrome. Chromosomes that have PCS will have their centromeres separate during metaphase rather than anaphase (one phase earlier than normal chromosomes). The second chromosomal abnormality is called heterochromatin repulsion (HR). Chromosomes that have HR experience separation of the heterochromatic regions during metaphase. Chromosomes with these two abnormalities will display a "railroad track" appearance because of the absence of primary constriction and repulsion at the heterochromatic regions. The heterochromatic regions are the areas near the centromeres and nucleolar organizers. Carrier status cannot be determined by cytogenetic testing. Other common findings of cytogenetic testing on Roberts syndrome patients are listed below.

- Aneuploidy- the occurrence of one or more extra or missing chromosomes

- Micronucleation- nucleus is smaller than normal

- Multilobulated Nuclei- the nucleus has more than one lobe