Duchenne's muscular dystrophy is the most common form of respiratory diseases.

Symptoms appear in male children before the age of3. In other words, children with this particular disease develop symptoms normally during 1-2 years, but as they turn 2-3, their muscles start to weaken and they walk in an odd way. They also do a duck walk or walk on their toes. Patients often visit a hospital at the age of 3-7.
Some other examples of a muscular disease include Becker's muscular dystrophy, limb-girdle muscular dystrophy, congenital muscular disease, etc.

The most important factors in diagnosing a muscular disease are a thorough understanding of the patient's medical history, a medical examination by an interview in regards to the family history and a detailed physical and neurological examination.
More specifically, a doctor must examine which part of the body the patient experiences a weakening or shrinking of muscles, whether it is amyotrophic or distal area, symmetrical or asymmetrical, progressive or non-progressive, or whether the age of onset was infancy, early childhood, adolescence or adulthood. It is also critical to check the family history, whether it is X-linked recessive, autosomal recessive, autosomal dominant or mitochondria genetic.
The most important of all is a muscle biopsy. With this technique, one can distinguish whether it is a neurological disease or muscular disease through various tissues staining and identify different types of muscular diseases by obtaining all the other information.
In addition to such, with the development of the gene diagnosis, its importance is also increasing and now it is possible to genetically diagnose Duchenne's muscular dystrophy, Becker's muscular dystrophy and myotonic dystrophy.

Complication of the respiratory system is the most fatal complication and the most common cause of death. The primary respiratory issues with the patients are a reduced amount of inspiratory air caused by weakened inspiratory muscles and a declined coughing ability caused by weakened expiratory muscles.
Therefore, it is necessary to supplement the functions of the respiratory system through the use of a supplemental apparatus for respiratory muscles and expiratory muscles.