In post-menopausal women, the walls of the vagina become thinner (atrophic vaginitis). The mechanism for the age-related condition is not yet clear, though there are theories that the effect is caused by decreases in estrogen levels. This atrophy, and that of the breasts concurrently, is consistent with the homeostatic (normal development) role of atrophy in general, as after menopause the body has no further functional biological need to maintain the reproductive system which it has permanently shut down.

One drug in test seemed to prevent the type of muscle loss that occurs in immobile, bedridden patients.

Testing on mice showed that it blocked the activity of a protein present in the muscle that is involved in muscle atrophy. However, the drug's long-term effect on the heart precludes its routine use in humans, and other drugs are being sought.

A 2006 study followed 223 patients for a number of years. Of these, 15 died, with a median age of 65 years. The authors tentatively concluded that this is in line with a previously reported estimate of a shortened life expectancy of 10-15 years (12 in their data).

Neuromuscular disease is a very broad term that encompasses many diseases and ailments that impair the functioning of the muscles, either directly, being pathologies of the voluntary muscle, or indirectly, being pathologies of nerves or neuromuscular junctions.

Neuromuscular diseases are those that affect the muscles and/or their direct nervous system control, problems with central nervous control can cause either spasticity or some degree of paralysis (from both lower and upper motor neuron disorders), depending on the location and the nature of the problem. Some examples of central disorders include cerebrovascular accident, Parkinson's disease, multiple sclerosis, Huntington's disease and Creutzfeldt–Jakob disease. Spinal muscular atrophies are disorders of lower motor neuron while amyotrophic lateral sclerosis is a mixed upper and lower motor neuron condition.

The genetics of congenital muscular dystrophy are autosomal recessive which means two copies of an abnormal gene must be present

for the disease or trait to happen. In the case of collagen VI-deficient, it is autosomal dominant, which means a child could inherit the disease from only one copy of a gene present in only one parent.

The prevalence for congenital muscular dystrophy seems to be between 2.6-4.5 in 10,000 according to Reed, 2009. MDCIA, for example is due to a mutation in the LAMA-2 gene and is involved with the 6q2 chromosome.

Neuromuscular disease can be caused by autoimmune disorders, genetic/hereditary disorders and some forms of the collagen disorder Ehlers–Danlos Syndrome, exposure to environmental chemicals and poisoning which includes heavy metal poisoning. The failure of the electrical insulation surrounding nerves, the myelin, is seen in certain deficiency diseases, such as the failure of the body's system for absorbing vitamin B-12

Diseases of the motor end plate include myasthenia gravis, a form of muscle weakness due to antibodies against acetylcholine receptor, and its related condition Lambert-Eaton myasthenic syndrome (LEMS). Tetanus and botulism are bacterial infections in which bacterial toxins cause increased or decreased muscle tone, respectively.Muscular dystrophies, including Duchenne's and Becker's, are a large group of diseases, many of them hereditary or resulting from genetic mutations, where the muscle integrity is disrupted, they lead to progressive loss of strength and decreased life span.

Further causes of neuromuscular diseases are :

Inflammatory muscle disorders

- Polymyalgia rheumatica (or "muscle rheumatism") is an inflammatory condition that mainly occurs in the elderly; it is associated with giant-cell arteritis(It often responds to prednisolone).

- Polymyositis is an autoimmune condition in which the muscle is affected.

- Rhabdomyolysis is the breakdown of muscular tissue due to any cause.

Tumors

- Smooth muscle: leiomyoma (benign)

- Striated muscle: rhabdomyoma (benign)

The importance of correctly recognizing progressive muscular atrophy as opposed to ALS is important for several reasons.

- 1) the prognosis is a little better. A recent study found the 5-year survival rate in PMA to be 33% (vs 20% in ALS) and the 10-year survival rate to be 12% (vs 6% in ALS).

- 2) Patients with PMA do not suffer from the cognitive change identified in certain groups of patients with MND.

- 3) Because PMA patients do not have UMN signs, they usually do not meet the "World Federation of Neurology El Escorial Research Criteria" for “Definite” or “Probable” ALS and so are ineligible to participate in the majority of clinical research trials such as drugs trials or brain scans.

- 4) Because of its rarity (even compared to ALS) and confusion about the condition, some insurance policies or local healthcare policies may not recognize PMA as being the life-changing illness that it is. In cases where being classified as being PMA rather than ALS is likely to restrict access to services, it may be preferable to be diagnosed as "slowly progressive ALS" or "lower motor neuron predominant" ALS.

An initial diagnosis of PMA could turn out to be slowly progressive ALS many years later, sometimes even decades after the initial diagnosis. The occurrence of upper motor neurone symptoms such as brisk reflexes, spasticity, or a Babinski sign would indicate a progression to ALS; the correct diagnosis is also occasionally made on autopsy.

In terms of the mechanism of congenital muscular dystrophy, one finds that though there are many types of CMD the glycosylation of α-dystroglycan and alterations in those genes that are involved are an important part of this conditions pathophysiology

Spinal and bulbar muscular atrophy (SBMA) is a progressive debilitating neurodegenerative disorder resulting in muscle cramps and progressive weakness due to degeneration of motor neurons in the brainstem and spinal cord.

The condition is associated with mutation of the androgen receptor ("AR") gene and is inherited in an X-linked recessive manner. As with many genetic disorders, no cure is known, although research continues. Because of its endocrine manifestations related to the impairment of the "AR" gene, SBMA can be viewed as a variation of the disorders of the androgen insensitivity syndrome (AIS). It is also related to other neurodegenerative diseases caused by similar mutations, such as Huntington's disease.

This condition is rare with an estimated incidence of 1/40,000 males. Although this condition is not normally fatal eventually 20% of those affected may need a wheelchair.

Muscular dystrophy (MD) is a group of muscle diseases that results in increasing weakening and breakdown of skeletal muscles over time. The disorders differ in which muscles are primarily affected, the degree of weakness, how fast they worsen, and when symptoms begin. Many people will eventually become unable to walk. Some types are also associated with problems in other organs.

There are nine main categories of muscular dystrophy that contain more than thirty specific types. The most common type is Duchenne muscular dystrophy (DMD) which typically affects males beginning around the age of four. Other types include Becker muscular dystrophy, facioscapulohumeral muscular dystrophy, and myotonic dystrophy. They are due to mutations in genes that are involved in making muscle proteins. This can occur due to either inheriting the defect from one's parents or the mutation occurring during early development. Disorders may be X-linked recessive, autosomal recessive, or autosomal dominant. Diagnosis often involves blood tests and genetic testing.

There is no cure for muscular dystrophy. Physical therapy, braces, and corrective surgery may help with some symptoms. Assisted ventilation may be required in those with weakness of breathing muscles. Medications used include steroids to slow muscle degeneration, anticonvulsants to control seizures and some muscle activity, and immunosuppressants to delay damage to dying muscle cells. Outcomes depend on the specific type of disorder.

Duchenne muscular dystrophy, which represents about half of all cases of muscular dystrophy, affects about one in 5,000 males at birth. Muscular dystrophy was first described in the 1830s by Charles Bell. The word "dystrophy" is from the Greek "dys", meaning "difficult" and "troph" meaning "nourish". Gene therapy, as a treatment, is in the early stages of study in humans.

Spinal muscular atrophies (SMAs) are a genetically and clinically heterogeneous group of rare debilitating disorders characterised by the degeneration of lower motor neurons (neuronal cells situated in the anterior horn of the spinal cord) and subsequent atrophy (wasting) of various muscle groups in the body. While some SMAs lead to early infant death, other types permit normal adult life with only mild weakness.

Fukuyama congenital muscular dystrophy has a poor prognosis. Most children with FCMD reach a maximum mobility at sitting upright and sliding. Due to the compounded effects of continually worsening heart problems, impaired mental development, problems swallowing and additional complications, children with FCMD rarely live through adolescence, the disorder proves fatal by age 20.

Limb-girdle muscular dystrophy (LGMD) or Erb's muscular dystrophy is a genetically and clinically heterogeneous group of rare muscular dystrophies. It is characterised by progressive muscle wasting which affects predominantly hip and shoulder muscles. LGMD has an autosomal pattern of inheritance and currently has no known cure.

Despite being rarer than ALS, PMA was described earlier, when in 1850 French neurologist François Aran () described 11 cases which he termed "atrophie musculaire progressive". Contemporary neurologist Guillaume-Benjamin-Amand Duchenne de Boulogne also claimed to have described the condition 1 year earlier, although the written report was never found. The condition has been called progressive muscular atrophy (PMA), spinal muscular atrophy (SMA), Aran–Duchenne disease, Duchenne–Aran disease, Aran–Duchenne muscular atrophy, and Duchenne–Aran muscular atrophy. The name "spinal muscular atrophy" is ambiguous as it refers to any of various spinal muscular atrophies, including the autosomal recessive spinal muscular atrophy caused by a genetic defect in the "SMN1" gene.

Oculopharyngeal muscular dystrophy (OPMD) is a rare form of muscular dystrophy with symptoms generally starting when an individual is 40 to 50 years old. It can be autosomal dominant neuromuscular disease or autosomal recessive. The most common inheritance of OPMD is autosomal dominant, which means only one copy of the mutated gene needs to be present in each cell. Children of an affected parent have a 50% chance of inheriting the mutant gene.

Autosomal dominant inheritance is the most common form of inheritance. Less commonly, OPMD can be inherited in an autosomal recessive pattern, which means that two copies of the mutated gene need to be present in each cell, both parents need to be carriers of the mutated gene, and usually show no signs or symptoms. The PABPN1 mutation contains a GCG trinucleotide repeat at the 5' end of the coding region, and expansion of this repeat which then leads to autosomal dominant oculopharyngeal muscular dystrophy (OPMD) disease.

Based on the type of muscles affected, spinal muscular atrophies can be divided into:

- "Proximal spinal muscular atrophies", i.e., conditions that affect primarily proximal muscles;

- "Distal spinal muscular atrophies" (which significantly overlap with distal hereditary motor neuronopathies) where they affect primarily distal muscles.

When taking into account prevalence, spinal muscular atrophies are traditionally divided into:

- "Autosomal recessive proximal spinal muscular atrophy", responsible for 90-95% of cases and usually called simply "spinal muscular atrophy" (SMA) – a disorder associated with a genetic mutation on the "SMN1" gene on chromosome 5q (locus 5q13), affecting people of any age but in its most severe form being the most common genetic cause of infant death;

- "Localised spinal muscular atrophies" – much more rare conditions, in some instances described in but a few patients in the world, which are associated with mutations of genes other than "SMN1" and for this reason sometimes termed simply "non-5q spinal muscular atrophies".

A more detailed classification is based on the gene associated with the condition (where identified) and is presented in table below.

In all forms of SMA (with an exception of X-linked spinal muscular atrophy type 1), only motor neurons, located at the anterior horn of spinal cord, are affected; sensory neurons, which are located at the posterior horn of spinal cord, are not affected. By contrast, hereditary disorders that cause both weakness due to motor denervation along with "sensory" impairment due to sensory denervation are known as hereditary motor and sensory neuropathies (HMSN).

Several gene mutations have been identified in patients with camptocormia. These include the RYR1 gene in axial myopathy, the DMPK gene in myotonic dystrophy, and genes related to dysferlinopathy and Parkinson’s disease. These genes could serve as targets for gene therapy to treat the condition in the years to come.

A multitude of neurological disorders cause BSS, including motor neuron disease, CNS disorders, and early amyotrophic lateral sclerosis. Usually, the bent spine is caused by dysfunctioning extensor spinal muscles with a neurological cause.

Neurological origin BSS may also result from damage to the basal ganglia nuclei that are a part of the cerebral cortex, which play a major role in bodily positioning. Damage to this part of the brain can inhibit proper flexion and extension in the muscles necessary for maintaining an upright position. Additionally, the neurotransmitter dopamine plays a key role in the operation of basal ganglia. An abnormally low dopamine concentration, such as that associated with Parkinson’s disease, causes dysfunction in the basal ganglia and the associated muscle groups, leading to BSS. Studies have estimated the prevalence of BSS in people affected by Parkinson's to be between 3% and 18%.

The disease is found across 5 continents (30 countries) and is frequently seen in French Canadians, with a prevalence 1:1000. OPMD affects males and females equally, and affected individuals have been found in Europe (France), Jewish Ashkenazi, and Spanish Americans.

Duchenne muscular dystrophy is a rare progressive disease which eventually affects all voluntary muscles and involves the heart and breathing muscles in later stages. As of 2013, the life expectancy is estimated to be around 25, but this varies. With excellent medical care males are often living into their 30s.

In rare cases, people with DMD have been seen to survive into their forties or early fifties, with proper positioning in wheelchairs and beds, and the use of ventilator support (via tracheostomy or mouthpiece), airway clearance, and heart medications. Early planning of the required supports for later-life care has shown greater longevity for people with DMD.

Curiously, in the mdx mouse model of Duchenne muscular dystrophy, the lack of dystrophin is associated with increased calcium levels and skeletal muscle myonecrosis. The intrinsic laryngeal muscles (ILMs) are protected and do not undergo myonecrosis. ILMs have a calcium regulation system profile suggestive of a better ability to handle calcium changes in comparison to other muscles, and this may provide a mechanistic insight for their unique pathophysiological properties. The ILM may facilitate the development of novel strategies for the prevention and treatment of muscle wasting in a variety of clinical scenarios.

In terms of the genetics LGMD is an inherited disorder, though it may be inherited as a dominant or recessive genetic defect. The result of the defect is that the muscles cannot properly form certain proteins needed for normal muscle function. Several different proteins can be affected, and the specific protein that is absent or defective identifies the specific type of muscular dystrophy. Among the proteins affected in LGMD are α, β, γ and δ sarcoglycans. The sarcoglycanopathies could be possibly amenable to gene therapy.

These conditions are generally inherited, and the different muscular dystrophies follow various inheritance patterns. Muscular dystrophy can be inherited by individuals as an X-linked disorder, a recessive or dominant disorder. Furthermore, it can be a spontaneous mutation which means errors in the replication of DNA and spontaneous lesions. Spontaneous lesions are due to natural damage to DNA, where the most common are depurination and deamination.

Dystrophin protein is found in muscle fibre membrane; its helical nature allows it to act like a spring or shock absorber. Dystrophin links actin in the cytoskeleton and dystroglycans of the muscle cell plasma membrane, known as the sarcolemma (extracellular). In addition to mechanical stabilization, dystrophin also regulates calcium levels.

Recent studies on the interaction of proteins with missense mutations and its neighbors showed high degree of rigidity associated with central hub proteins involved in protein binding and flexible subnetworks having molecular functions involved with calcium.

Becker muscular dystrophy is an X-linked recessive inherited disorder characterized by slowly progressive muscle weakness of the legs and pelvis. It is a type of dystrophinopathy. This is caused by mutations in the dystrophin gene, which encodes the protein dystrophin. Becker muscular dystrophy is related to Duchenne muscular dystrophy in that both result from a mutation in the "dystrophin" gene.

Possible complications associated with MD are cardiac arrhythmias.(BMD) Becker muscular dystrophy also demonstrates the following:

- Mental impairment (less common in BMD than it is in DMD.)

- Pulmonary failure

- Pneumonia

X-linked spinal muscular atrophy type 2 (SMAX2, XLSMA), also known as arthrogryposis multiplex congenita X-linked type 1 (AMCX1), is a rare neurological disorder involving death of motor neurons in the anterior horn of spinal cord resulting in generalised muscle wasting (atrophy). The disease is caused by a mutation in "UBA1" gene and is passed in a X-linked recessive manner by carrier mothers to affected sons.

Affected babies have general muscle weakness, weak cry and floppy limbs; consequently, the condition is usually apparent at or even before birth. Symptoms resemble the more severe forms of the more common spinal muscular atrophy (SMA); however, SMAX2 is caused by a different genetic defect and only genetic testing can correctly identify the disease.

The disorder is usually fatal in infancy or early childhood due to progressive respiratory failure, although survival into teenage years have been reported. As with many genetic disorders, there is no known cure to SMAX2. Appropriate palliative care may be able to increase quality of life and extend lifespan.