Halsey has spent eight years fighting for a diagnosis for their health issues.
The 27-year-old singer revealed earlier this week they had been diagnosed with Ehlers-Danlos syndrome, Sjogren's syndrome, mast cell activation syndrome, and postural orthostatic tachycardia syndrome and the 'Control' hitmaker has now claimed they were repeatedly dismissed as "crazy and anxious" after multiple visits to doctors over the years in a quest to find out what was wrong.
They wrote on their Instagram Story: "I just want to clarify, for the benefit of friends of friends who may have any of the diagnosis that I recently shared, I didn't 'just get sick.' I've been sick. For a long time. My sicknesses just have their names now.
"I went to doctors for 8 years. Trying to figure out what was wrong with me. I was called crazy and anxious and lazy amongst other things. I changed my entire lifestyle. When I wasn't working I was essentially confined to my home for fear of how I'd feel when I woke up each morning."
"It took me a long time to get to even having a diagnosis so I'm celebrating!! Don't roll your eyes at your sick friends. They could be fighting a battle that they haven't named yet. Ya know?(sic)"
The 'Closer' singer - who has nine-month-old son Ender with Alev Aydin - previously explained her health had declined during her pregnancy.
She said: "Obviously my health has changed a lot since I got pregnant and gave birth. I started getting really, really, really, sick… I was hospitalized for anaphylaxis [a potentially life-threatening allergic reaction] a few times and I had some other stuff going on."
Halsey - who uses they/she pronouns - then revealed the various diagnoses they had been given but told fans not to "worry" and insisted her upcoming 'Love and Power' tour won't be affected.
They said: "I am on a treatment plan right now. I'm in rehearsals for the tour. I'm really excited and really confident that I'm going to be able to do it in a way that's healthy where I could perform my best for all of you, and honestly, I'm just so excited to be going on tour because it just keeps my mind off of everything and it keeps my body healthy because I'm just so active and doing cardio and stuff every day, and I get to see you guys."