A woman has been arrested on suspicion of assisting or encouraging suicide following the death of a man.
Police were called to an address on Blackburn Road in Clayton-le-Moors at 01:45 BST on Thursday due to concerns for the welfare of a man and a woman.
Inside officers found a 19-year-old man had died and a woman, 46, had serious injuries, Lancashire Police said.
The woman was given first aid at the scene before being taken to hospital where she is in a stable condition.
She has since been arrested on suspicion of assisting or encouraging suicide.
The incident is currently being treated as unexplained but there is nothing to suggest any other people are involved, the force added.
A post-mortem examination has been carried out on the man but the cause of death remains unascertained, the police spokesperson added.