Madonna uses a nebuliser to keep her voice in top shape on her 'MDNA' tour.

The 54-year-old singer relies on bag of medical items, such as a facial steamer, and natural remedies to ensure she can perform to her best every night and after a concert she inhales a special saline mist to hydrate her throat.

In an interview on Brazilian TV show 'Caldeirao do Huck' - which was conducted in the bathroom of a Miami hotel room - she said: ''Here in the toilet I have my facial streamer, with eucalyptus, to calm down my voice. I also get some ice on my knee, because my knees hurt a little bit after 88 shows, that's why dancing in high heels is not recommended! The tea is for my throat it is made with tree bark and cinnamon, lemon and honey things that are soothing.

''This is my nebuliser - I sometimes have to hit it to work - it has a saline solution which hydrates my vocal cords.''

Madonna also has several other items she can't do without when she is on the road and she relies on a 1980s cassette player to do her vocal exercises.

The 'Hung Up' hitmaker gets sent tapes by her vocal coach in New York to warm up to and she won't upgrade to modern MP3 files because she says the recordings don't then work as well.

She revealed: ''My vocal coach in New York makes me cassettes for warm-ups and cool downs. This is how you survive a hundred shows. If I put on an iPad it doesn't work, you have to stop, it doesn't flow. And you have to put headphones on and then you can't hear your voice in the room. Maybe this technology will make a comeback.''