The 20-year-old influencer shared his health journey Monday -- this after a fan on TikTok speculated he may have the disorder. As Landon detailed in the video above ... he has a minor case of Tourette's -- which he says he was initially diagnosed with as a child.

Landon recalled first experiencing Tourette's back in preschool ... after a teacher accused him of rolling his eyes at her. Travis' son -- whom he shares with Shanna Moakler -- explained the eye-rolling was eventually diagnosed as a tic ... a symptom of the neurological condition.

He went on to describe his tics -- which also include jerking his head to the side and moving his jaw repeatedly -- stuff he'll do when he says he's nervous or anxious.

On why he decided to share his diagnosis now ... Landon said he just felt like sharing his truth -- and fans have since applauded him for his candor.

Landon has been opening up about his personal life quite a bit in recent weeks ... having previously confirmed his split from TikToker girlfriend Charli D'Amelio in February.

At the time ... Landon told fans that he and Charli split on good terms -- as they're taking time to focus on themselves.