A female friend is thought to have called an ambulance to Moore's Beverly Hills home after she began shaking and appeared to be having a seizure - resulting in the star being hospitalised.
According to tabloid, a source told a US website: "She collapsed after having an epileptic seizure. Demi is getting treated for anorexia and other issues. She has not taken care of her health lately and has lost a ton of weight."
Despite these reports, Moore's spokeswoman has insisted that Demi is seeking treatment for exhaustion, stating: "Because of the stresses in her life right now, Demi has chosen to seek professional assistance to treat her exhaustion and improve her overall health.
"She looks forward to getting well and is grateful for the support of her family and friends."