In her recent critically-acclaimed movie Cake, Jennifer Aniston plays a woman suffering from chronic pain. In real life, though, the actress has dealt with another kind of life-altering condition: dyslexia.

This week, the former Friends star revealed to The Hollywood Reporter that she was diagnosed with the reading disorder in her 20s.

People with dyslexia typically have trouble identifying the sounds of speech, making it hard to pronounce words, read aloud, and recognize rhyme, says Sally E. Shaywitz, MD, author of Overcoming Dyslexia: A New and Complete Science-Based Program for Reading Problems at Any Level ($14.27, amazon.com)Other key symptoms include delayed speech, problems with spelling, and slow reading speed.

If not caught early, dyslexia can take a toll on self-esteem. "I thought I wasn't smart. I just couldn't retain anything," Aniston told THR. "Now I had this great discovery. I felt like all of my childhood trauma-dies, tragedies, dramas were explained."

RELATED: 9 Ways to Silence Your Inner Critic

This is true for many children with dyslexia. "When children enter school and see other kids in their class doing things they can't do, it can feel awful," says Dr. Shaywitz, who is also co-director of the Yale Center for Dyslexia and Creativity.

The cause of dyslexia is still unknown, says Gail Saltz, MD, Health's contributing psychology editor. And the language processing disorder is life long.

"It's not treatable in the sense you can make it go away," Dr. Saltz says. "But you can become a more fluent reader by being taught specific skills or learning your own workarounds to do it a different way."

That's why an early diagnosis can be crucial. "The younger you are the more plastic your brain is for building those skills," Dr. Saltz says.

RELATED: 17 Ways to Age-Proof Your Brain

While it's unfortunate Aniston wasn't diagnosed sooner, spotting dyslexia in grade school is more likely today than it was a few decades ago.

"People knew much less," says Dr. Saltz. "Today teachers are much more trained on picking up that the issue is specifically with reading, so hopefully it's diagnosed in elementary school." It usually happens around the third or fourth grade, Dr. Shaywitz adds.

Aniston's dyslexia wasn't caught until she had a routine exam for prescription glasses, reports THR. While an eye doctor could theoretically confirm vision problems aren't to blame for poor reading, it's more common for children to see a psychologist or learning specialist to sort out symptoms, Dr. Saltz says.

First, the expert would start by getting a history of the child's language development and spelling. Then, they'd observe reading and speaking skills. A child might take tests to measure intelligence, and be evaluated for reading speed and the ability to discern individual sounds.

RELATED: 12 Worst Habits For Your Mental Health

"The hallmark of dyslexia is a difficulty with reading but the child is usually very bright," Dr. Shaywitz says. "So the intelligence test plus reading and language tests will give you a very good idea of whether a person is dyslexic."

Bottom line: Having dyslexia doesn't mean you're not intelligent, and like Aniston, people with dyslexia can have plenty of talent to spare.