Fungal Infections

Authored by , Reviewed by Dr John Cox | Last edited | Meets Patient’s editorial guidelines

A fungus is a germ that ranges from something tiny and barely visible all the way to something big like a mushroom. They are all around us and don't usually cause any problems.  Sometimes they can cause itchy skin infections which are treated with creams or tablets.

Occasionally fungi (which is the plural of fungus) can cause more serious infections, particularly if you are already ill. This can happen if you are taking medicines that lower your immune system, like chemotherapy.

A fungus is just a type of germ. They can range from tiny, barely visible specks that float around in the air, all the way up to large growths like mushrooms. Fungi (the plural of fungus) are all around us and don't usually cause any problems. However occasionally they can settle down and grow in places where they shouldn't: places on our bodies like our skin, nails, between our toes and, in women, the vaginal area. This can happen even in people who are fairly healthy and is usually easy to treat with creams or pills.

Occasionally if someone's immune system is weak because they are battling cancer or on chemotherapy, fungi can grow in their lungs. This then needs specialist treatment with strong antifungal medications either by pills or by infusions into a vein. See the separate leaflet called Fungal Lung Infections.

Probably the most common thing fungi do to the body is cause annoying, itchy skin problems:

The thing that is common to fungal skin infections is that they tend to be itchy rather than painful and often make the skin a bit flaky. They are not contagious: you can't catch it by touching the other person's skin. Although they are annoying and irritating, they are not usually serious.

Fungal nail infections

It is quite common to develop a fungal nail infection on the toenails. Almost every elderly person will have it to some degree but children hardly ever get it. The symptoms of fungal nail infections are:

  • Nails turning white.
  • Nails becoming flaky and brittle.
  • Nails growing into a curved-over shape instead of being fairly flat.

A lot of people have these problems on their toenails. Much like the skin fungal infections, it is annoying to have this on your toes but not harmful or painful. The creams and liquids you can buy in shops are not usually effective for fungal toenail infections: if you really want to get rid of it you probably need the antifungal tablet called terbinafine. As this medicine has its own side-effects and can interfere with any other medicine you might be taking, it is only available on prescription. See the separate leaflet called Fungal Nail Infections (Tinea Unguium).

It is less common to have fungal nail infections on your fingernails. Usually this is related to your work, perhaps having wet fingers a lot of the day (as in hairdressers or farmers). Occasionally your fingernails can change if there is something else wrong with your body, like an underlying condition, so it's worth seeing your doctor before trying to treat your own fingernails.

Where else in the body can fungi cause problems?

Occasionally fungi can grow in someone's ear canal, if they do a lot of swimming or diving or live in a humid environment. Sometimes fungi can grow in someone's lungs. This is serious and is usually related to the person already having a weak immune system, such as having cancer or receiving chemotherapy.

A fairly common condition, in which a fungus grows in a woman's vagina, causes an itchy sensation and usually some vaginal discharge. This is called vaginal thrush and has a number of treatments ranging from a cream or a tablet to changes to your diet. See the separate leaflet called Vaginal Thrush (Yeast Infection).

There is a rare condition called aspergillosis where a fungus causes an allergic reaction in your lungs and causes problems with breathing. This requires a specialist to diagnose and treat it. See the separate leaflet called Fungal Lung Infections.

Like a lot of things in medicine, there are plenty of myths around fungi. Something that's caught hold in the last decade or so is the idea of having the fungus called candida floating around in your bloodstream, infecting your whole body. This is then blamed for common problems like irritability, fatigue, indigestion, headaches and sleep problems.

Unfortunately there has never really been any proof that 'systemic candida' (as it's called) really exists. If you have questions about these symptoms it's best to speak with an impartial doctor you trust, rather than spend money on strange and expensive diets.

Antifungal Medicines