Leg weakness isn't unusual when you've been exercising aggressively or when you're suffering from a bout of the flu. But when you start to notice that your legs feel weak all the time whenever you climb stairs, then it may indicate a more serious underlying condition. Don't assume your experience is just a part of aging, and head to a doctor as soon as possible to determine the cause and get appropriate treatment.
Addison's Disease
Addison's disease is a disorder that occurs when your body produces inadequate amounts of adrenal gland hormones, causing muscle weakness and fatigue, muscle or joint pains, weight loss, skin darkening, and low blood pressure. It's an autoimmune disease, and in most cases, the cause is unknown. Treatment includes steroids and androgen replacement therapy.
Amyotrophic Lateral Sclerosis
Amyotrophic lateral sclerosis, also known as Lou Gehrig's disease, is a disease of the nerve cells in the brain and spinal cord that control voluntary muscle movement, in which the cells waste away and die. There is no cure, and patients eventually are unable to move and may even be unable to breathe. Prognosis isn't good, but certain medications can help alleviate symptoms.
Blood Clots
Blood clots are clumps that occur when the blood hardens inside a blood vessel, most often inside the lower leg. Pieces of the clot may break off and travel to the heart, lungs or brain, which is called an embolism. Symptoms can include leg pain, heaviness and weakness, sometimes accompanied by swelling, heat to the touch and discoloration. Treatment includes blood-thinning medications.
Charcot-Marie-Tooth Disease
Charcot-Marie-Tooth disease is an inherited neurological disorder. It causes damage to the covering around nerve fibers and may lead to weakness in your lower leg muscles or foot and deformities such as hammertoes or high arches. There is no known cure, and treatment includes braces and physical therapy.
Femoral Nerve Compression
The femoral nerve runs from your spine into your thigh and helps supply sensation and the ability to move the quadriceps muscles. Injuries, diabetes and inflammation can damage the nerve and cause groin and leg pain and weakness walking upstairs. Treatment depends upon the cause of the condition.
Herniated Disk
A herniated disk refers to a condition when one of the rubbery cushions between the individual bones in your spine pushes out through a crack in the exterior and irritates nerves, causing pain, numbness or weakness. Therapy includes pain medications, steroid injections, physical therapy and, in rare cases, surgery.
Multiple Sclerosis
Multiple sclerosis causes the degeneration of the central nervous system, although the reason is unknown. MS leads to muscle weakness in extremities and difficulty with coordination and balance, as well as vision problems. It can be mild or severe, and there is no cure, although medications can be given to help with muscle stiffness and spasms.
Peripheral Artery Disease
Peripheral artery disease, or PAD, is a common circulatory problem in which narrowed arteries reduce blood flow to your limbs. In addition to leg numbness or weakness, you may experience painful cramping in your hip, thigh or calf muscles after climbing stairs or walking. Medications, angioplasty, surgery and lifestyle changes are typically prescribed.
Polymyositis
Polymyositis is an autoimmune muscle disease with chronic muscle inflammation accompanied by muscle weakness that starts in the muscles closest to the trunk of your body. It eventually leads to difficulties climbing stairs, rising from a seated position or reaching overhead. There is no cure, but medication, physical therapy, exercise and heat therapy can help with symptoms.
References
- MayoClinic.com; Addison's Disease; June 2010
- PubMed Health; Amyotrophic Lateral Sclerosis; August 2010
- University of Maryland Medical Center; Blood Clots; June 2008
- PubMed Health; Charcot-Marie-Tooth Disease; August 2009
- Podiatrist Brisbane: Femoral Nerve Compression
- MayoClinic.com; Herniated Disc; December 2010


