5 scary bacteria and fungi hiding under your long nails

Long nails are bold and glamorous, but beneath them lie bacteria and fungi that could harm your health. According to Jeffrey Kaplan, a biology professor at American University, long nails, whether natural, gel polish, acrylic, or press-ons, create the perfect hiding spot for potentially harmful microorganisms.

“The longer the nail, the more surface area there is for microorganisms to adhere,” Kaplan told USA Today. In fact, studies have discovered at least 32 types of bacteria and 28 types of fungi living under fingernails.

Washing your hands doesn’t always help. “Even after handwashing or surgical scrubbing, bacteria often remain under the nails,” Kaplan warned.

5 Common Bacteria and Fungi Found Under Nails

1. MRSA (Methicillin-Resistant Staphylococcus aureus)

One of the most concerning bacteria found under nails is MRSA, a drug-resistant strain of staph that can cause severe skin infections, pneumonia, and even bloodstream infections. According to Kaplan, one study found MRSA beneath half of all fingernail samples tested.

2. Staphylococcus aureus

This is commonly found on skin; this bacterium can easily make its way under your nails. When introduced to the body through a scratch, bite, or broken skin, it can cause boils, abscesses, and cellulitis, a painful skin infection.

3. Pseudomonas aeruginosa

This bacterium thrives in moist environments, making nail beds an ideal home. It can cause nail discolouration (green nails) and chronic infections, especially if the nail plate lifts from the nail bed.

4. Candida albicans

A common yeast found in the body, Candida can lead to nail infections, particularly in those with weakened immune systems. Signs include swelling around the nails, pain, and a thickened or discoloured nail plate.

5. Dermatophytes

These fungi are responsible for onychomycosis, or fungal nail infections, which make the nail brittle, crumbly, and sometimes smelly. They thrive in warm, moist environments, like under long or artificial nails.

How These Microorganisms Affect Your Health

Nail bacteria and fungi aren’t just gross; they can be dangerous. Here are some health risks linked to poor nail hygiene:

Nail Infections (Paronychia or Onychomycosis): Painful, swollen, and pus-filled, these infections occur when bacteria or fungi enter through a tear in the skin around the nail. Chronic infections may leave nails discoloured, thick, and permanently damaged.
Skin Infections: If you scratch your skin, bite your nails, or pick your nose (yes, really), you risk transferring bacteria like staph or MRSA into your body, leading to serious infections.
Risk in Medical Settings: Long nails can be a hidden danger in healthcare environments. Two nurses in Oklahoma were linked to the deaths of 16 infants in the late 1990s, with bacteria traced back to the areas beneath their nails. While the connection was not conclusively proven, the findings led to stricter hygiene policies for medical staff.

How to Keep Your Nails Clean and Safe

You don’t have to give up on gorgeous nails to stay healthy—just follow these hygiene and maintenance tips:

Keep It Clean – Regularly clean under your nails using a soft nail brush and warm, soapy water. Pay extra attention after activities like gardening, cooking, or using public transport.
Trim or Refill Regularly – Whether your nails are natural or artificial, schedule routine trims or salon visits to prevent lifting, which creates a pocket for bacteria to thrive.
Avoid Nail Biting and Picking – These habits break the skin and allow bacteria direct entry into your system.
Practice Good Salon Hygiene – Ensure your nail technician uses sterilised tools. Don’t be afraid to ask how tools are cleaned.
Go Bare Occasionally – Give your nails a break from polish or extensions now and then to air out and recover.
Moisturise Your Cuticles – Dry, cracked skin around the nails makes it easier for germs to enter. Keep your hands and cuticles moisturised.