We now know what Janet Jackson is canceling so many of her scheduled tour dates. People Magazine is reporting that Jackson is struggling with vestibular migraines.

Vestibular migraines aren't just headaches. This is actually a rare condition that causes vertigo.

Janet's manager Kenneth Cread said the singer is "feeling much better and is ready to hit the road again."

She will resume her Rock Witchu Tour Wednesday night in Washington D.C.

The tour dates that were canceled due to Jackson's illness will be be rescheduled at a later date.