“ALS is a relentlessly progressive disorder. The rate of progression between individuals is variable and the history generally reflects gradual and progressive worsening over time until death occurs.  The initial symptoms of ALS can vary considerably from person to person, as can the rate at which ALS progresses. Not all individuals with ALS develop the same symptoms or the same sequences or patterns of progression. However, all people with ALS will experience progressive muscle weakness and paralysis; so there are different stages with ALS. About 60% of the people reported to have ALS in the United States are men, and 93% of patients are Caucasian.  It is estimated that as many as 30,000 Americans have the disease at any given time.  Most people develop ALS between the ages of 40 and 70, with an average age of 55 at the time of diagnosis. However, rare cases of the disease do occur in persons in their 20s and 30s.”

HHS