Male 20 yrs old.left leg has felt weird for a year. im terrified its als, but i went to a neurologist 1 week ago and he said everything looked okay..

Many causes: Many things, that are not life threatening, or disabling, can cause altered sensation in a leg. Start with your primary care doc, and if there are no systemic answers, see a physiatrist. As long as you are not getting weakness or progressive dysfunction, the symptoms should be manageable.

Other issues: I would not think at 20, after assessment by neurologist, and isolated single limb parasthesias would be als. There are many causes and ALS is one of the more rare causes. You could have back issues that are mildy irritating a nerve that may be giving you these feelings. Do you have any close family members with als? Any history of continuous head injuries? If no to both of these, less likely.