Toenail Fungus: Signs, Tests and Treatment in Spain
Medically Reviewed by Dr. Pedro Yelamo Vera, MD
Licensed Physician No. 484814280 · Official Medical College of Bizkaia (Spain)Last reviewed: 29 October 2026
Toenail fungus explained: how to tell it apart, why a nail test matters, realistic cure rates, what Spanish pharmacies sell and when to see a doctor.
You don't have to figure this out alone
Dr. Pedro Yelamo Vera is an independent, bilingual GP licensed in Spain. Book a 15-minute video consultation in English or Spanish for €50, with a private electronic prescription issued under Spanish law when clinically appropriate.
Toenail fungus (onychomycosis) makes a nail thick, yellow or white, and crumbly. It is common and rarely serious, but slow to clear. Not every odd-looking nail is fungal: only about half are. A nail sample test is worth doing before tablets. Lacquers suit mild cases; tablets work better but need a prescription.
- Fungus causes only about half of thick or discoloured nails. Psoriasis and injury can look the same.
- A nail clipping or scraping test confirms it. Doctors advise this before oral treatment.
- Antifungal nail lacquers help mild cases, but full cure rates are low.
- Oral antifungals work better. They need a prescription and often a liver blood test.
- A clear nail takes a year or more to grow out, and the fungus can come back.
- With diabetes, poor circulation or a weak immune system, see a doctor rather than self-treat.
Dr. Pedro Yelamo Vera is a GP licensed in Spain (Colegiado No. 484814280).
For a medical emergency, call 112 or go to the nearest local emergency department. Do not wait for a video consultation or an online reply.
What does toenail fungus look like?
It usually starts at the tip or the side of the big toenail. MedlinePlus lists these changes:
- A thicker nail that is hard to cut.
- White or yellow streaks, or a dull, discoloured nail.
- Crumbly or ragged edges, with debris under the nail.
- A nail that lifts away from the skin underneath.
Often there is no pain at all. In Spain you will hear it called hongos en las uñas or onicomicosis.
Is it really fungus, or something else?
This is the key question. The Spanish clinical guide Fisterra notes that fungus explains about half of all nail problems, and that doctors often over-diagnose it by eye. Other causes look very similar:
- Nail psoriasis, which can thicken and lift the nail too.
- Repeated knocks from tight shoes, running or a past injury.
- Age, as nails get thicker and more ridged.
That is why a nail test matters. A small clipping or scraping goes to the lab. The fungus is looked for under a microscope and grown in culture. MedlinePlus says the culture can take 4 to 6 weeks. Tablets act on the whole body, so it makes sense to confirm the cause first.
A dark brown or black stripe in the nail is different. It is usually a bruise. If it has no clear cause, show it to a doctor, because rarely it is a melanoma.
What causes it, and who gets it?
The fungi that cause athlete's foot often spread from the skin into the nail. Warm, damp shoes help them grow. MedlinePlus and the Cochrane reviews list these risk factors:
- Athlete's foot, or a family history of fungal nails.
- Older age.
- Diabetes, poor circulation or nerve damage in the feet.
- A weak immune system.
- Shared showers at pools and gyms, and shoes that do not breathe.
- A nail that was already damaged.
Which treatments work, and how well?
The aim is a healthy nail growing from the base. The damaged part has to grow out.
| Treatment | What the evidence shows |
|---|---|
| Antifungal nail lacquer (amorolfine, ciclopirox) | Cochrane found topical treatments help, but full cure rates are fairly low. Best for mild cases near the tip. |
| Oral terbinafine | The most effective option in the Cochrane review of oral treatment. Needs a prescription. |
| Oral itraconazole (an azole) | Works, but less well than terbinafine in that review. Needs a prescription. |
| Laser | MedlinePlus says it is less effective than medicine. Cochrane found the evidence uncertain. |
| Creams for athlete's foot | Treat the skin between the toes, but MedlinePlus says they usually do not clear the nail. |
Even with tablets, MedlinePlus says the fungus clears in about half of people. It can also come back after a good result. A very damaged nail is sometimes removed, under a local anaesthetic.
Can you buy a toenail fungus treatment without a prescription in Spain?
Partly. At least one amorolfine nail lacquer is listed on the AEMPS CIMA database as non-prescription, sold only in pharmacies. The status can differ between brands, so ask the pharmacist. The non-prescription product sheet says not to use it under 18, or in pregnancy or breastfeeding, unless a doctor advises it. It also says people with diabetes, poor circulation or immune problems should see a doctor first.
The ciclopirox nail lacquers listed on CIMA are prescription medicines. Terbinafine tablets need a prescription in Spain. Some terbinafine creams are sold without one, but many brands need a prescription. Our prescription status guide covers this. In the UK, a pharmacist can sell an amorolfine lacquer. In the US, amorolfine is not sold.
Not sure whether your nail is fungal?
You can book a video visit with a GP licensed in Spain, in English or Spanish. He looks at the nail on camera and explains whether a test, a lacquer or tablets make sense.
Why might you need a blood test for tablets?
Rarely, oral antifungals affect the liver. The Spanish product sheet for terbinafine says to check liver function before prescribing. The NHS says a blood test may be needed before and during treatment. Tablets are not suitable for everyone, for example with liver or kidney disease. They interact with some medicines, so bring your list. Our guide to liver enzyme results explains what the test shows.
How long does a toenail take to grow out?
Nails grow slowly, about 1 to 2 mm a month, according to the Spanish Academy of Dermatology (AEDV). MedlinePlus says a new clear toenail can take up to a year to grow. For a big toenail it is often longer. So you judge success by a clear band of new nail at the base, not by the old tip.
How can you stop it coming back?
- Treat athlete's foot early, so it does not spread to the nails.
- Dry well between the toes and wear clean socks each day.
- Wear flip-flops in pool and gym showers.
- Choose shoes that fit and breathe.
- Do not share towels, shoes or nail clippers.
When should you see a doctor?
- You have diabetes, poor circulation or numb feet. Foot problems are more serious then. Read about diabetes care.
- Your immune system is weak, for example after a transplant or during chemotherapy.
- The nail hurts, or the skin around it turns red, swollen or leaks pus.
- Several nails are affected, or pharmacy treatment has not helped.
- A child's nail looks fungal. Children are rarely affected, so check the cause.
- You are pregnant or breastfeeding.
Call 112 or go to urgencias if a red, hot, swollen foot comes with fever or you feel very unwell. This matters most with diabetes, where a foot infection can spread.
Talking it through with a doctor by video
Dr. Yelamo is a GP licensed in Spain. He sees adults, children and pregnant patients by video, every day from 07:30 to 20:30 (Spain time). In the visit he will:
- Look at the nails and the skin between your toes on camera.
- Ask about diabetes, circulation and the medicines you take.
- Explain whether a nail test is worth doing first, and how to get one.
- Talk through a lacquer or tablets, and what results to expect.
He does not promise any test or prescription before the visit. Where clinically appropriate, following a genuine evaluation. Treatment and prescriptions are issued solely at the doctor's discretion based on evidence-based clinical guidelines.
A prescription is never guaranteed: it is issued only where clinically appropriate after a genuine evaluation, as a private electronic prescription under Spanish law. This service is for urgent, non-emergency care. In an emergency, call 112.
See how the Urgent Care video visit works. It lasts 15 minutes and costs €50.
This guide is general information. It does not replace a consultation with your doctor or the package leaflet of any medicine.
Frequently asked questions
Is toenail fungus contagious?
It can spread from athlete's foot to the nails, and between people through damp floors, shoes and towels. Flip-flops in shared showers and not sharing towels lower the risk.
Do I need a nail test before treatment?
It is wise before tablets. Only about half of abnormal-looking nails are fungal, and a clipping or scraping test confirms the cause.
Can I buy amorolfine lacquer without a prescription in Spain?
Some amorolfine lacquers are non-prescription and sold only in pharmacies; others may need a prescription, so ask the pharmacist. They are not for under-18s, or for pregnancy, unless a doctor advises it.
Do terbinafine tablets need a prescription in Spain?
Yes. The tablets need a prescription, and the doctor usually checks a liver blood test first. Some terbinafine creams are sold without one; many need a prescription.
How long until my toenail looks normal?
A new clear toenail can take a year or longer to grow out. Success shows as healthy nail at the base, not at the tip.
Does toenail fungus go away on its own?
Usually not, but it is rarely harmful. If it does not bother you and you have no diabetes or circulation problems, leaving it untreated is a reasonable choice.
Should I worry if I have diabetes?
See a doctor rather than self-treat. Foot problems are more serious with diabetes, and a fungal nail can let bacteria in.
Sources
- NHS: Fungal nail infection, treatment
- MedlinePlus: Nail fungal infection
- Cochrane: Oral antifungal medication for toenail onychomycosis
- Cochrane: Topical and device-based treatments for toenail fungus
- AEMPS CIMA: amorolfine nail lacquer product sheet (Spanish)
Related guides
Medical Citations & Sources
This content is written and reviewed by a licensed physician with reference to the following official health authorities.
