Poorna was born in a Muslim family to Kassim and Ramla Beevi. She did her high school studies from Ursuline Senior Secondary School, Kannur and later moved to St. Teresas, Kannur to concentrate more on her dancing skills. She has four siblings: Sheriffa, Arifa, Shanavas and Shaina. She has completed a Bachelor of Arts in English by correspondence.
Poorna made her acting debut in the 2004 Malayalam film Manju Poloru Penkutty and went on to play minor supporting roles in a couple of unsuccessful films. She played her first major role in her debut Telugu film Sri Mahalakshmi, while playing the lead female character in her first Tamil film, Muniyandi Vilangial Moonramandu. In the mid 2010, she appeared in a series of films where she portrayed a ghost. She won critical acclaim for her roles in Avunu and the sequel Avunu 2. She turned down several similar scripts, before winning further acclaim for her role as a ghost in Raju Garu Gadhi which became a surprise sleeper hit at the box office. Her future projects are Savarakkaththi, Sarvamangalam, Manal Kayiru 2, Okkasari Avunu Okasari Kaadhu Arjunan Kadhali Padam Pesum.