Weakness: Check Your Symptoms and Signs With the Symptom Checker by MedicineNet.com

Weakness Symptoms

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Terms related to Weakness:

Arm Weakness
Leg Weakness
Loss of Strength
Muscle Pain and Weakness
Muscle Weakness
Weakness in Arms
Weakness in Legs

Weakness is a decrease in the strength in one or more muscles. In the strictest sense, the medical definition of weakness refers to loss of muscle strength, and this article is focused upon conditions that can result in a measurable loss of muscle function. Weakness may be generalized or may affect one muscle or muscle group exclusively. Diseases of the neuromuscular system, injuries, metabolic diseases, and toxins can all cause of measurable muscle weakness.

Many people use the term weakness as a synonym for tiredness, although this is not technically correct. People suffering from certain medical conditions (for example, cancer or influenza) may describe feelings of total body weakness, referring to feelings of malaise or tiredness, even though no detectable loss of muscle strength is present.

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Causes of Weakness

Addison's Disease Addison disease is a hormonal (endocrine) disorder involving destruction of the adrenal glands (small glands adjacent to the...learn more »
Amyotrophic Lateral Sclerosis (ALS) Amyotrophic lateral sclerosis (ALS, Lou Gehrig's disease) is a neurological disease that progresses rapidly. The disease attacks...learn more »
Ankle Pain and Tendinitis Ankle pain is commonly due to a sprain or tendinitis. The severity of ankle sprains ranges from mild (which can resolve within...learn more »
Botulism Botulism is an illness caused by a neurotoxin produced by the bacterium Clostridium botulinum. There are three types of botulism:...learn more »
Cerebral Palsy Cerebral palsy (CP) is an abnormality of motor function and postural tone acquired at an early age (even before birth). Cerebral...learn more »
Charcot-Marie-Tooth-Disease Charcot-Marie-Tooth disease is one of the most common inherited neurological disorders. Charcot-Marie-Tooth disease affects the...learn more »
Chickenpox (Varicella) Chickenpox (chicken pox) is a contagious childhood disease caused by the varicella-zoster virus. Symptoms have an incubation...learn more »
Diabetic Neuropathy Diabetic Neuropathy is a complication of diabetes that causes damage to the nerves; this is related to the blood glucose of the...learn more »
Facial Nerve Problems and Bell's Palsy Facial nerve disorders affect the muscles of the face. There are many causes of facial nerve disorders including: trauma, nervous...learn more »
Guillain-Barre Syndrome Guillain-Barre Syndrome is an autoimmune disease of the nervous system due to damage to the myelin sheath around nerves. It is...learn more »
Hodgkin's Disease Hodgkin's disease is a cancer of the lymphatic system with symptoms that include unexplained, recurring fevers, unexplained...learn more »
Multiple Myeloma Multiple myeloma is a form of cancer that develops in plasma cells, the white blood cells that make antibodies. Symptoms include...learn more »
Multiple Sclerosis Multiple sclerosis (MS) is a disease which progressively injures the nerves of the brain and spinal cord, reflected by...learn more »
Myasthenia Gravis Myasthenia gravis, a chronic autoimmune neuromuscular disease. Varying degrees of weakness of the voluntary muscles of the body...learn more »
Non-Hodgkin's Lymphoma Non-Hodgkin's lymphoma is cancer of the lymphatic system, a vital part of the body's immune system. Symptoms include swollen...learn more »
Norovirus Infection Norovirus infection causes stomach flu, or gastroenteritis. It's a very contagious illness with symptoms that include nausea and...learn more »
Plague Plague is an infectious disease caused by the Yersinia pestis bacteria, which is primarily found in rodents the fleas that feed...learn more »
Polymyositis Polymyositis is a disease of the muscle featuring inflammation of the muscle fibers. It results in weakness of the muscles which...learn more »
Rocky Mountain Spotted Fever Rocky Mountain spotted fever (RMSF) is an infectious disease that's transmitted by the bite of a tick infected with the...learn more »
Sprains and Strains An injury to a ligament is called a sprain, and an injury to muscle or tendon is called a strain. Sprains and strains may be...learn more »
Stroke A stroke results from impaired oxygen delivery to brain cells via the bloodstream. A stroke is also referred to as a CVA, or...learn more »
Torn Meniscus A torn meniscus (knee cartilage) may be caused by suddenly stopping, sharply twisting, or deep squatting or kneeling when lifting...learn more »
Vitamin D Deficiency Vitamin D deficiency has been linked with rickets, cancer, cardiovascular disease, severe asthma in children and cognitive...learn more »
West Nile Virus West Nile virus (West Nile encephalitis) is a brain infection caused by a virus. People become infected with the virus after...learn more »
Yellow Fever Yellow fever is an infectious disease transmitted by infected mosquitoes. Side effects are rare with the yellow fever vaccine....learn more »

Other Causes of Weakness

Examples of Medications for Weakness