What is ALS? Former NFL star Chris Johnson reveals his diagnosis

Former Tennessee Titans and Arizona Cardinals running back Chris Johnson publicly disclosed his amyotrophic lateral sclerosis (ALS) diagnosis.

Commonly known as Lou Gehrig’s disease, it destroys motor neurons in the brain and spinal cord that control voluntary muscle actions.

As these nerve cells deteriorate, they fail to send messages to muscles. As a result, muscles become weaker, twitch, atrophy, and finally rob one of the abilities to move, speak, swallow, and even breathe.

The 39-year-old opened up his diagnosis in an interview with ABC’s “Good Morning America” that aired Monday, June 29.

While speaking through a speech-generating device based on recordings of his voice, he said, “There’s no history of ALS in my family. My doctors believe my case is what’s called sporadic ALS, which is actually how the vast majority of ALS cases happen.”

“That’s one of the reasons this disease can be so shocking. It can happen to someone who never expected it,” he added.

The former running back, whose title "CJ2K" was coined due to the 2,006 yards he accumulated in 2009, the seventh highest yardage gained in a season in NFL history, revealed that his problems started when he noticed he had a weak grip.

While talking about the rapid progression of this disease, he said: “Just over a year ago, I was picking up my 7-year-old daughter so she could make a wish with he birthday cake. Today, I couldn’t do that.”

Early symptoms of the disease include limb weakness, motor control issues, and unexplained muscle cramps. slurred speech, trouble projecting the voice, and minor difficulty swallowing. Over time, the patient faces severe difficulty chewing, swallowing, and speaking clearly. Excessive drooling is also common.

The disease currently has no known cure.