Kourtney Kardashian threw up "four or five times" during her post-birthday celebrations.

The reality TV star - who turned 38 on April 18 - has admitted to over-indulging on alcohol during a belated birthday bash in Mexico, where she is currently on vacation with her friends and sister Kim.

Kourtney wrote on Twitter: "I may or may not have thrown up four times last night and slept in it. #birthdayvibes (sic)"

Meanwhile, the brunette beauty - who has Mason, seven, Penelope, four, and two-year-old son Reign with her ex-boyfriend Scott Disick - was wished a happy birthday by various family members last week, including her mother Kris Jenner.

The showbiz matriarch wrote on Instagram: "From the day you were born you have blessed me with so much joy! You bring happiness love and light and are such an inspiration to me, and everyone around you. You are such an incredible mother, sister, friend, and daughter and I love you more than words can ever say.... you are beautiful inside and out my sweet girl, have an amazing day, mommy xoxo #love #family #grateful #happybirthdaykourtney. (sic)"

Elsewhere, Kim wrote on her own website: "Happy Birthday to the best older sister. I'm so blessed to have you in my life. I love how close we were growing up - and still are today. I don't know what I would do without you! Love you!"

Kim also took to Twitter to mark the occasion, writing: "Happy Birthday to the one and only @kourtneykardash My best friend, the best mom and the best sister in the world! (sic)"

Meanwhile, Kourtney's half-sister Kendall Jenner also sent her best wishes.

Writing on her website, the 21-year-old model said: "I hope you have the best birthday, Kourtney!!! You do so much for everyone else, so I hope you take the day to treat yourself. I love you! (sic)"