rihanna-smoking-terry-richardson.jpg RiRi is under the weather yet again!

Rihanna was forced to cancel her Monday concert in Houston, Texas, due to an undisclosed illness, forcing promoter Live Nation to issue refunds to thousands of disappointed fans.

You would think the Barbados-born beauty would have at least taken to her Twitter account to apologize and offer some sort of explanation, but apparently not!

The singer is reportedly suffering from laryngitis. Maybe she should cut back on all those nights partying at Greystone Manor?

"Rihanna's illness was so severe that doctors warned it could take months for her to fully recover - there were worries that she'd have to cancel her entire tour. They've told her that she needs to make some serious lifestyle changes, or risk this happening again. This has given her a scare. But Rihanna knows it's self-inflicted. She loves to smoke, drink and stay up late. Her body was bound to need a break at some point. She's now on a mission to start looking after herself," a source told The Sun.

Get well soon girl!