What Are the Signs and Symptoms of Muscular Dystrophy?

Muscular dystrophy isn’t one disorder, but rather a group of more than 30 types of genetic conditions that cause progressive muscle weakness and loss. Although the signs and symptoms of muscular dystrophy vary from type to type, there are some common characteristics shared among them.

Some forms of muscular dystrophy are diagnosed in infancy or childhood, while the symptoms of others may not start in adults until they reach middle age.

The different types of muscular dystrophy can vary in terms of who they affect, which muscles they affect, and what their symptoms are. However, all forms of muscular dystrophy become increasingly worse, or progress — meaning your muscles get weaker the longer you have the condition.

As a result, most people with muscular dystrophy eventually lose the ability to walk. Still, some people with the condition have mild cases that progress more slowly, while other cases quickly become severe and disabling.

In general, talk to your doctor if you notice signs of muscle weakness — such as clumsiness or falling — in yourself or your child.

Depending on what type of muscular dystrophy you have — and the age at which you’re diagnosed — you may experience some of the following symptoms:

• Muscle weakness
• Difficulty walking
• Frequent falling
• Difficulty getting up from a lying or sitting position
• Limited movement at certain joints (called contracture)
• Heart problems
• Problems with breathing and swallowing
• Muscle pain or stiffness

Earlier-onset forms of muscular dystrophy are also associated with developmental delays and intellectual disability.

Duchenne muscular dystrophy (DMD) is the most common and severe form of muscular dystrophy in children, accounting for more than one-half of all cases of the disorder in this age group. It’s typically diagnosed in children ages 3 to 5, and it progresses rapidly, eventually leaving those diagnosed unable to walk by their early teens and, later, requiring a respirator to breathe.

DMD is more common in boys, although girls are also mildly affected. It’s caused by a deficiency in the protein dystrophin, which helps strengthen muscle fibers and protect them from injury, according to the the Muscular Dystrophy Association (MDA).

Children who develop DMD usually begin experiencing weakness in their upper legs and pelvis. Symptoms of DMD and muscular dystrophy in children may include:

• Early onset of symptoms (by age 2 or 3)
• Muscle weakness in the trunk, arms, and legs
• Frequent falls
• Difficulty rising from a lying or sitting position
• Problems running and jumping
• A “waddling” gait
• Appearing to walk on tiptoes
• Enlarged calf muscles
• Heart and lung problems
• Muscle pain and stiffness
• Learning disabilities in some (but not all) children
• Delayed growth

Like DMD, Becker muscular dystrophy is also caused by dystrophin deficiency. However, it tends to be less severe and progress more slowly than DMD, and is usually diagnosed in teens and young adults.

Becker muscular dystrophy causes similar symptoms as DMD, notes the Mayo Clinic, with a couple of typical differences:

• Later onset of symptoms (teens, twenties, and thirties)
• Muscle weakness starts in the arms and later affects the legs and sometimes facial muscles

Some people with Becker muscular dystrophy may never need to use a wheelchair, while others lose the ability to walk during their teens, mid-thirties, or later.

Limb-girdle muscular dystrophy strikes during adolescence or young adulthood. The condition usually progresses slowly, but most people will eventually become severely disabled due to muscle damage.

They may be unable to walk within 20 years of being diagnosed.

Most people with this form of muscular dystrophy first develop weakness around their hips and shoulders. Low back pain is a common symptom. Contractures (limited movement at the joints), breathing issues, and heart problems may also occur in some individuals.

Congenital muscular dystrophy refers to a subset of muscular dystrophies that are apparent at or closely following birth. It affects boys and girls equally.

Babies with congenital muscular dystrophy may require support to sit or stand and may never learn to walk. Some children with congenital muscular dystrophy die in infancy, but others live into adulthood with only mild disability.

There are actually more than 30 subtypes of congenital muscular dystrophy, according to the MDA. However, about 30 to 40 percent of all cases of the disorder in the United States involve merosin-deficient congenital muscular dystrophy (MDC1A), which is caused by a defect in the protein merosin, according to the National Library of Medicine.

Merosin surrounds muscle fibers to protect them from damage or injury.

Babies with MDC1A will experience:

• Decreased muscle tone (hypotonia)
• Breathing and swallowing problems
• Problems with motor function and muscle control
• Developmental delay
• Scoliosis (or curvature of the spine)
• Chronic shortening of muscles or tendons around joints (contractures), which prevents joints from moving freely
• Seizures

Myotonic dystrophy is the most common adult form of muscular dystrophy, notes the MDA. It causes an inability to relax muscles following a sudden contraction, as well as:

• Swallowing difficulties
• Drooping eyelids
• Cataracts and other vision problems
• Baldness at the front of the scalp
• Weight loss
• Increased sweating
• Fatigue
• Infertility or impotence

Some types of myotonic dystrophy may also affect the heart, eyes, pancreas, and other organs.

Most people with myotonic dystrophy are diagnosed in their twenties or thirties.

Another type of muscular dystrophy that may strike adults is facioscapulohumeral dystrophy (FSHD). It typically affects teens, although it may occur in adults up to 40 years old.

Muscle weakness with FSHD usually begins in the face, hip, and shoulders, affecting the eyes and mouth. People with FSHD may have:

• Difficulty opening and shutting their eyes
• Trouble smiling or puckering their lips
• Muscle wasting that causes their shoulders to appear slanted
• “Popeye arms” because of muscle atrophy of the upper arm and sparing of the forearm muscles
• Difficulty swallowing, chewing, or speaking
• Hearing loss

The condition may also cause a curvature in the spine, called lordosis.

RELATED: Your Everyday Guide to Living Well With Muscular Dystrophy