Why Apple Watch has issues with tattoos

Apple CEO Tim Cook introduces the Apple Watch during an Apple event in San Francisco, California March 9, 2015. (REUTERS/Robert Galbraith)

Tattoo ink is one of several issues that Apple has acknowledged with the Apple Watch.

Though Apple has not yet responded to a query from FoxNews.com about anecdotal evidence that tattoo ink can interfere with the ability of the watch’s sensor to get notifications and read your heart rate, there is an Apple support page that addresses the latter -- heart rate.

The support page spells out potential problems – not exclusive to tattoos. “Many factors can affect the performance of the Apple Watch heart rate sensor,” the Apple page states.

“Skin perfusion” – which describes how much blood flows through your skin – is one factor.

“Skin perfusion varies significantly from person to person and can also be impacted by the environment. If you’re exercising in the cold, for example, the skin perfusion in your wrist may be too low for the heart rate sensor to get a reading,” the Apple support page states.

Irregular movements can also affect readings from the heart rate sensor. “Rhythmic movements, such as running or cycling, give better results compared to irregular movements, like tennis or boxing,” the Apple page states.

Last but not least Apple addresses tattoos.

“Permanent or temporary changes to your skin, such as some tattoos, can also impact heart rate sensor performance. The ink, pattern, and saturation of some tattoos can block light from the sensor, making it difficult to get reliable readings,” according to Apple.

Apple’s support pages, however, do not address the potentially larger issue of notifications.

That issue has been trending on social media. Threads on sites like Reddit and Twitter point to a potential problem with the ink interfering with notifications and causing the watch to “lock," preventing the pings that alert a user to notifications.

“The watch would lock up every time the screen went dark and prompted me for my password. I wouldn't receive notifications," said one commenter on Reddit.

Other commenters, who had similar experiences, seemed to support the claim.

The topic has also been trending on Twitter under the hashtag #tattoogate.