A man has been arrested after a woman was found unconscious at an address in Rhondda Cynon Taf.
Emergency services were called to Meyler Street in Tonyrefail just before 13:00 BST.
The 33-year-old woman has been taken to hospital where she is being treated for serious injuries, South Wales Police said.
The force said a 36-year-old man had been arrested on suspicion of grievous bodily harm.