An online social networking website has been used from the other side of the globe to alert emergency services to a Dunedin woman experiencing an epileptic fit.

Two lovers, Melody Madiland in Dunedin and Anna Messner in the US state of Tennessee, were on a video call on Tuesday afternoon.

However, Ms Madiland, who has a history of epilepsy, began to have a seizure.

"She slams back into her pillow because she’s lying on a mattress, and her mouth starts frothing," Ms Messner said.

"She's breathing irregularly and I can see her lips turn blue."

Ms Madiland was home alone, and her finance couldn’t call internationally to raise the alarm.

But, social networking site Reddit came to the rescue.

Ms Messner’s brother, also in Tennessee, comes up with the idea to post the emergency to Reddit.

The call for help is seen online in Christchurch by Jana Hayes and a call for help is made.

"I looked at it and I was like I'm not really sure if it’s real or y'know if it’s a joke," she said.

She dialled 111 and an ambulance was sent to MS Madiland’s home just 45 minutes after the seizure began.