Weakness
Lack of strength; Muscle weakness
Weakness is reduced strength in one or more muscles.
Causes
Weakness may be all over the body or in only one area. Weakness is more noticeable when it is in one area. Weakness in one area may occur:
- After a stroke
- After injury to a nerve
-
During a flare-up of
multiple sclerosis (MS)
Multiple sclerosis (MS)
Multiple sclerosis is an autoimmune disease that affects the brain and spinal cord (central nervous system).
You may feel weak but have no real loss of strength. This is called subjective weakness. It may be due to an infection such as the flu. Or, you may have a loss of strength that can be noted on a physical exam. This is called objective weakness.
Weakness may be caused by diseases or conditions affecting many different body systems, such as the following:
METABOLIC
-
Adrenal glands not producing enough hormones (
Addison disease
)
Addison disease
Addison disease is a disorder that occurs when the adrenal glands do not produce enough hormones.
-
Parathyroid glands producing too much parathyroid hormone (
hyperparathyroidism
)
Hyperparathyroidism
Hyperparathyroidism is a disorder in which the parathyroid glands in your neck produce too much parathyroid hormone (PTH).
- Low sodium or potassium
-
Overactive thyroid (
thyrotoxicosis
)
Thyrotoxicosis
Hyperthyroidism is a condition in which the thyroid gland makes too much thyroid hormone. The condition is often called overactive thyroid.
BRAIN/NERVOUS SYSTEM (NEUROLOGIC)
-
Disease of the nerve cells in the brain and spinal cord (
amyotrophic lateral sclerosis
; ALS)
Amyotrophic lateral sclerosis
Amyotrophic lateral sclerosis, or ALS, is a disease of the nerve cells in the brain, brain stem and spinal cord that control voluntary muscle movemen...
-
Weakness of the muscles of the face (
Bell palsy
)
Bell palsy
Bell palsy is a disorder of the nerve that controls movement of the muscles in the face. This nerve is called the facial or seventh cranial nerve. D...
-
Group of disorders involving brain and nervous system functions (
cerebral palsy
)
Cerebral palsy
Cerebral palsy is a group of disorders that can involve brain and nervous system functions, such as movement, learning, hearing, seeing, and thinking...
-
Nerve inflammation causing muscle weakness (
Guillain-Barre syndrome
)
Guillain-Barre syndrome
Guillain-Barré syndrome is a serious health problem that occurs when the body's defense (immune) system mistakenly attacks part of the nervous system...
- Multiple sclerosis
- Pinched nerve (for example, caused by a slipped disk in the spine)
- Stroke
MUSCLE DISEASES
-
Becker muscular dystrophy
Becker muscular dystrophy
Becker muscular dystrophy is an inherited disorder that involves slowly worsening muscle weakness of the legs and pelvis.
-
Dermatomyositis
Dermatomyositis
Dermatomyositis is a muscle disease that involves inflammation and a skin rash. It is a type of inflammatory myopathy.
-
Muscular dystrophy
(Duchenne)
Muscular dystrophy
Muscular dystrophy is a group of inherited disorders that cause muscle weakness and loss of muscle tissue, which get worse over time.
- Myotonic dystrophy
POISONING
-
Botulism
Botulism
Botulism is a rare but serious illness caused by Clostridium botulinum bacteria. The bacteria may enter the body through wounds, or by eating them f...
-
Poisoning (
insecticides
, nerve gas)
Insecticides
Insecticide is a chemical that kills bugs. Insecticide poisoning occurs when someone swallows or breathes in this substance or it is absorbed throug...
-
Shellfish
poisoning
Shellfish
This article describes a group of different conditions caused by eating contaminated fish and seafood. The most common of these are Ciguatera poison...
OTHER
-
Not enough healthy red blood cells (
anemia
)
Anemia
Anemia is a condition in which the body does not have enough healthy red blood cells. Red blood cells provide oxygen to body tissues. Different type...
-
Disorder of the muscles and nerves that control them (
myasthenia gravis
)
Myasthenia gravis
Myasthenia gravis is a neuromuscular disorder. Neuromuscular disorders involve the muscles and the nerves that control them.
-
Polio
Polio
Polio is a viral disease that can affect nerves and can lead to partial or full paralysis. The medical name for polio is poliomyelitis.
Home Care
Follow the treatment your health care provider recommends to treat the cause of the weakness.
When to Contact a Medical Professional
Call your provider if you have:
- Sudden weakness, especially if it is in one area and does not occur with other symptoms, such as fever
- Sudden weakness after being ill with a virus
- Weakness that does not go away and has no cause you can explain
- Weakness in one area of the body
What to Expect at Your Office Visit
The provider will do a physical exam. Your provider will also ask you about your weakness, such as when it began, how long it has lasted, and whether you have it all the time or only at certain times. You may also be asked about medicines you take or if you have been ill recently.
The provider may pay close attention to your heart, lungs, and thyroid gland. The exam will focus on the nerves and muscles if the weakness is only in one area.
You may have blood or urine tests. Imaging tests such as x-ray or ultrasound may also be ordered.
References
Raftery AT, Lim E, Ostor AJK. Muscle weakness and wasting. In: Raftery AT, Lim E, Ostor AJK, eds. Churchill's Pocketbook of Differential Diagnosis . 4th ed. Philadelphia, PA: Elsevier; 2014:334-337.
Selcen D. Muscle diseases. In: Goldman L, Schafer AI, eds. Goldman-Cecil Medicine . 25th ed. Philadelphia, PA: Elsevier Saunders; 2016:chap 421.
Review Date: 7/13/2016
Reviewed By: Linda J. Vorvick, MD, Medical Director and Director of Didactic Curriculum, MEDEX Northwest Division of Physician Assistant Studies, Department of Family Medicine, UW Medicine, School of Medicine, University of Washington, Seattle, WA. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.