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ALS (Amyotrophic Lateral Sclerosis)

Amyotrophic lateral sclerosis (ALS), also known as Lou Gehrig's disease, is a progressive nervous system disease that affects nerve cells in the brain and spinal cord, causing loss of muscle control. It often begins with muscle twitching and weakness in a limb or slurred speech.

Neurological
  • What exactly is ALS (also called Lou Gehrig's disease) and why does it cause muscle weakness?
    MedlinePlusJun 2026

    ALS (amyotrophic lateral sclerosis), also known as Lou Gehrig's disease, is a progressive neurological disease that destroys the nerve cells (motor neurons) that control voluntary muscle movement. Over time, this leads to increasing muscle weakness, paralysis, and eventually affects the ability to speak, swallow, and breathe.

  • Why do the nerve cells that control my muscles stop working in ALS?
    MedlinePlusJun 2026

    In ALS, the motor neurons in the brain and spinal cord that send signals telling muscles to move gradually die off. Without these signals, muscles weaken and waste away. The disease progresses to affect more and more muscle groups over time, though intellect, memory, and the senses (sight, hearing, touch, smell) typically remain intact.

  • Does ALS run in families?
    MedlinePlusJun 2026

    About 90 to 95 percent of ALS cases are sporadic—meaning they appear without a clear family history and are likely caused by a combination of genetic susceptibility and environmental factors. About 5 to 10 percent are familial (inherited), caused by mutations in specific genes like SOD1, C9orf72, or FUS.

  • How fast does ALS usually progress?
    MedlinePlusJun 2026

    ALS most often begins between the ages of 40 and 70, though it can occur at any adult age. It affects men slightly more often than women, though the difference narrows with age. It is more common in Caucasians than other ethnic groups, and military veterans appear to have a higher risk than the general population.

  • Will ALS eventually affect my ability to breathe, swallow, or speak?
    MedlinePlusJun 2026

    ALS does not directly affect intellect, memory, or personality in most people. However, a subset of people with ALS (estimated at 10 to 15 percent) do develop frontotemporal dementia (FTD), a form of cognitive decline that affects personality and executive function. Most people with ALS remain fully cognitively intact throughout their illness.