Former NFL running back Chris Johnson, one of the fastest players in football history, has shared that he is living with ALS, a serious disease that affects the brain and the nerves that control muscles. Johnson announced his diagnosis during an emotional interview on Good Morning America, saying he was diagnosed last year after noticing weakness in his right hand.

Johnson, now 40, said he was healthy, exercising every day, and spending time with his wife and four children when his symptoms first began. At first, he thought something was wrong with his hand. His wife believed it might have been an old football injury. Instead, doctors found that he had ALS, also called Lou Gehrig’s disease.

“I had two choices,” Johnson said during the interview. “I could give up, or I could fight. I chose to fight.”

For many people, hearing the letters “ALS” can be confusing. So what exactly is it?

ALS is a disease that slowly damages the nerve cells that tell your muscles what to do. Think of your brain as the boss of your body. It sends messages through nerves that tell your arms to move, your legs to walk, and your mouth to talk. With ALS, those messages slowly stop working.

Imagine trying to turn on a lamp with a light switch, but the wire connecting the switch to the lamp is broken. The switch still works, but the message never reaches the light. That is similar to what happens in ALS. The brain still wants the body to move, but the nerves can no longer carry the message.

Over time, people with ALS may have trouble holding a cup, buttoning a shirt, walking, talking, swallowing food, or even breathing on their own. The disease affects the muscles, but it does not usually affect a person’s ability to think, remember, or love the people around them.

That is one reason Johnson wanted to share his story.

“I want people to know that I’m still me,” he said. “ALS has changed what my body can do, but it hasn’t changed who I am.”

Doctors do not know exactly what causes most cases of ALS. In about 90% of people diagnosed, there is no family history of the disease. This is called sporadic ALS, and it can happen to almost anyone.

Right now, there is no cure for ALS. However, some medicines may help slow the disease, and physical therapy, speech therapy, breathing support, and clinical trials can help people live longer and improve their quality of life. Researchers across the country continue working to find better treatments and, one day, a cure.

Although ALS is considered a rare disease, it can affect families in every community. Thousands of Americans are living with ALS today, and many rely on family members for daily care. Caregivers often help with meals, transportation, communication, and medical appointments as the disease progresses.

For communities of color, learning about diseases like ALS is important. Black and Hispanic families are sometimes diagnosed later with neurological diseases because symptoms may be mistaken for other health problems or because access to specialists can be limited. Early evaluation by a neurologist may help people receive treatment, supportive care, and information about clinical trials sooner.

Chris Johnson’s announcement is more than a sports story. It is a reminder that serious diseases do not always come with warning signs. Even someone who appeared strong, healthy, and active could develop a life-changing illness.

By sharing his journey, Johnson hopes more people will understand ALS, support research, and remember that behind every diagnosis is a person who still has dreams, hopes, and a family that loves them.