What your nails are telling you about your health: 7 warning signs

Ever noticed how some people can look at your hands and guess what you do for work? Well, your nails can tell an even more interesting story – about what’s happening inside your body. Sure, we all love a good manicure, but beyond the pretty colours, your nails are basically giving you a health report card every single day.

Here’s something that might surprise you: those little changes in how your nails look, feel, or grow? They’re often your body’s way of waving a flag about bigger health issues. Sometimes it’s nothing to worry about – maybe you just need more iron in your diet. Other times, it’s your early warning system telling you to book that doctor’s appointment you’ve been putting off.

We’ve helped thousands of Australians figure out what their nail changes mean through our teledermatology service. Most of the time, people come to us panicking over something completely normal. But occasionally, we catch something important early – and that makes all the difference.

So, let’s dive into seven nail changes that actually matter for your health.

1. Yellow, thick, or crumbling nails: Fungal infections and beyond

What you’re looking at: Your nails have gone yellow and gotten noticeably thicker, or maybe they’re starting to fall apart around the edges – not a good look.

What’s probably going on: Nine times out of ten, it’s a fungal infection, especially on your toes. Makes sense when you think about it – fungi absolutely thrive in those warm, sweaty shoe conditions we put our feet through every day. But here’s the thing: yellow nails aren’t always about fungus. They could also mean:

• Respiratory conditions like chronic bronchitis
• Lymphatic problems
• Thyroid disorders
• Diabetes complications

When to worry: If the yellowing spreads to multiple nails or doesn’t improve with over-the-counter antifungal treatments after several weeks, it’s time to seek professional help.

2. White spots or lines: Not just calcium deficiency

What you’re noticing: Little white spots scattered on your nails, or maybe some white lines running straight across them.

What’s actually happening: Okay, first let’s bust a myth – those white spots almost never mean you need more calcium, despite what your mom might have told you growing up. Most of the time, they’re just from bumping your nail or some other tiny injury you probably don’t even remember. But sometimes the pattern of these white marks can tell you something more important is going on:

• Horizontal white lines (Mees’ lines): May indicate arsenic poisoning, kidney disease, or chemotherapy effects
• White nails with pink tips (Terry’s nails): Could suggest liver disease, kidney failure, or heart conditions
• Completely white nails: Might indicate liver problems or anemia

When to worry: If white changes appear suddenly across multiple nails or form distinct horizontal bands, consult a healthcare provider.

3. Dark lines or spots: Melanoma risk

What you see: Dark brown or black lines running from the cuticle to the nail tip, or dark spots under the nail.

What it might mean: This is one of the most serious nail changes to watch for. Dark lines or spots can indicate:

• Subungual melanoma: A dangerous form of skin cancer under the nail
• Bacterial infections: Especially if accompanied by pain or swelling
• Medication side effects: Some drugs can cause nail pigmentation
• Normal pigmentation: More common in people with darker skin tones

When to worry: Any new dark line or expanding dark area under the nail needs immediate evaluation. Don’t wait – early detection of melanoma saves lives.

4. Spoon-shaped nails: Iron deficiency alert

What you see: Nails that curve inward, creating a spoon-like depression that could hold a drop of water.

What it might mean: Spoon nails (koilonychia) most commonly indicate iron deficiency anemia. Your body prioritises iron for essential functions, leaving nails weakened. Other possible causes include:

• Hemochromatosis: Your body’s hoarding too much iron – sounds good in theory, but it’s actually a problem
• Heart problems: When your heart isn’t pumping oxygen around your body like it should.
• Underactive thyroid: Your thyroid gland has basically gone on strike and isn’t doing its job properly.
• Raynaud’s disease: Poor blood flows to your hands and feet – you know how your fingers go white and numb in the cold? It’s like that, but more often.

Time to call the doctor: Spoon nails plus feeling exhausted all the time, looking pale as a ghost, or getting winded just walking upstairs? Yeah, that’s your cue to book some blood work and figure out what’s going on.

5. Clubbed fingertips: Oxygen and heart concerns

What you see: Fingertips that become enlarged and rounded, with nails that curve around the fingertips.

What it might mean: Clubbing often indicates your body isn’t getting enough oxygen. This can result from:

• Lung diseases: Including lung cancer, pulmonary fibrosis, or chronic infections
• Heart conditions: Congenital heart disease or heart infections
• Liver disease: Cirrhosis or other serious liver problems
• Inflammatory bowel disease: Crohn’s disease or ulcerative colitis

When to worry: Clubbing develops gradually but is always abnormal. If you notice your fingertips becoming rounder or your nails curving more than usual, seek medical attention promptly.

6. Horizontal ridges: Stress and serious illness

What you see: Deep horizontal grooves or ridges running across the nail from side to side.

What it might mean: These ridges (called Beau’s lines) form when nail growth temporarily stops or slows. Common causes include:

• Serious illness: Think of high fevers that knock you out for days, pneumonia that lands you in the hospital, or any infection that really takes it out of you.
• Big medical events: Major surgery, a bad accident, or any trauma that puts your body through the wringer.
• Cancer treatment: Chemo doesn’t just target the bad guys – it’s pretty brutal on everything, and your nails definitely get caught in the crossfire.
• Serious malnutrition: We’re talking about really not getting enough food or the right nutrients – your body starts rationing resources, and nails aren’t exactly a priority.
• Uncontrolled diabetes: When your blood sugar is on a roller coaster and your circulation suffers from it, your nails are just one of many things that pay the price.

When to worry: Since nails grow slowly, these ridges appear weeks after the triggering event. If you can’t identify a recent illness or stress, consult your healthcare provider.

7. Nail separation: Thyroid and skin conditions

What you see: The nail starts lifting away from the nail bed, creating a gap underneath.

What it might mean: Nail separation (onycholysis) can have various causes:

• Thyroid disorders: Both overactive and underactive thyroid.
• Psoriasis: The autoimmune skin condition often affects nails.
• Fungal infections: Advanced cases can cause separation.
• Contact dermatitis: Allergic reactions to nail products.
• Trauma: Injury from aggressive manicures or accidents.

When to worry: If separation affects multiple nails or occurs with other symptoms like skin changes or fatigue, professional evaluation is recommended.

When normal nail changes happen

Not every nail change signals a health problem. Normal variations include:

• Vertical ridges: Common with aging and usually harmless
• Slight color variations: Normal as long as they’re consistent
• Seasonal changes: Nails may grow faster in summer
• Minor white spots: Usually from small injuries you don’t remember

Taking Action: What You Can Do

If you notice concerning nail changes, here’s what to do:

• Document the changes: Take photos to track progression over time.
• Note accompanying symptoms: Fatigue, skin changes, or other health issues.
• Review your medications: Some drugs can affect nail appearance.
• Consider recent events: Illness, stress, or injury in the past few months.
• Seek professional help: Don’t ignore persistent or spreading changes.

How Dermo Direct can help

At Dermo Direct, our experienced dermatologists can evaluate your nail concerns through our convenient teledermatology service. We can:

• Assess whether nail changes need immediate attention
• Recommend appropriate diagnostic tests for your GP
• Provide treatment for nail conditions within our scope
• Guide you toward specialist care when needed

Many nail problems are easily treatable when caught early. Don’t worry about minor changes keeping you up at night, but don’t ignore warning signs either.

The bottom line

Your nails are remarkable indicators of your overall health. While most changes are harmless, some deserve prompt attention. Trust your instincts— if something seems wrong, it’s worth getting checked.

Remember, early detection and treatment lead to better outcomes for any health condition. Your nails might just be giving you valuable advance warning about your health.

Ready to get your nail concerns checked? Book a consultation with Dermo Direct today. Our Australian-based dermatologists are here to help you understand what your nails are really telling you about your health.