Are tattoos bad for your health? What the evidence shows about risks and care

A Swedish study published in 2024 observed a trend towards a roughly 21% higher lymphoma risk in tattooed people, but the result did not reach statistical significance and the authors themselves describe it as a possible association, still to be confirmed. What is demonstrated is something else: pigment does not stay only in the skin — some migrates to the regional lymph nodes. Inks can contain polycyclic aromatic hydrocarbons, primary aromatic amines and heavy metals. There is, today, no evidence allowing us to say that tattooing causes cancer. There are reasons to choose carefully where you tattoo and with which inks.

Do tattoos cause cancer?

The honest answer is: it is not known, and the available evidence does not demonstrate it.

The most cited study is from 2024, at Lund University, using Swedish population registries. It found a lymphoma incidence rate 1.21 times higher in people with tattoos — but with a 95% confidence interval running from 0.99 to 1.48.

This detail is decisive and almost always omitted: the lower limit crosses 1. In statistical terms, that means the result is compatible with there being no increase in risk at all. It is an observed trend, not an established effect.

The subtypes with the highest estimates — diffuse large B-cell lymphoma and follicular lymphoma — had confidence intervals that likewise overlapped 1.

A single observational study with this result does not establish causality. Factors such as smoking, occupational exposures or lifestyle may explain part of the association. The university itself presented the findings as a possible association.

What can be said with rigour: the hypothesis exists, it warrants investigation, and there is no answer yet.

Does tattoo ink go into the bloodstream?

It does not circulate freely in the blood, but nor does it all stay in the skin — and this part is well documented.

When ink is injected into the dermis, larger particles are retained in skin macrophages, which is what gives the design its permanence. The smaller particles are carried by the lymphatic system to the regional nodes, where they accumulate.

This is seen in clinical practice: lymph nodes in tattooed people can appear pigmented, in the colour of the corresponding ink. It is not rare, and pathologists know it well.

The most relevant practical consequence is not oncological — it is diagnostic. A pigmented node can be mistaken for melanoma metastasis on imaging or on biopsy. Your doctor should know there is a tattoo in the drained area.

What is in tattoo ink?

Composition varies widely between manufacturers, and that is where the real issue lies.

Inks can contain polycyclic aromatic hydrocarbons, particularly in black inks, which are genotoxic and classified as carcinogenic. They can contain primary aromatic amines, particularly in coloured pigments, also with carcinogenic potential. And they can contain heavy metals: arsenic, chromium, cobalt, lead and nickel.

Since 2022, the European Union's REACH regulation has restricted several of these substances in tattoo inks marketed within the European area. That improved matters, but does not eliminate variability — particularly in inks obtained outside legal channels.

The useful question is not "is the ink carcinogenic?" but "which ink is being used, and is it compliant?"

Do tattoos affect the immune system?

There is a local immune response, permanent and low-grade.

The body recognises pigment as a foreign body and mounts a response that never resolves, because the pigment cannot be eliminated. Macrophages take up the particles, die, and other macrophages take them up again — a cycle that continues for the life of the tattoo.

This low-grade inflammation is the biological basis underpinning the hypothesis under investigation. It does not mean it causes disease, and most tattooed people will never have any problem because of it.

Who should not get a tattoo?

There are situations where a tattoo is inadvisable or requires prior assessment:

• Psoriasis, lichen planus or vitiligo — new lesions can appear over the trauma, the Köbner phenomenon

• A tendency to keloid or hypertrophic scarring

• Active atopic dermatitis in the area to be tattooed

• Clotting disorders or anticoagulant therapy

• Immunosuppression, active cancer or ongoing chemotherapy

• Poorly controlled diabetes, because of impaired healing

• Active skin infection in the area

• Pregnancy and breastfeeding — as a precaution, not because of demonstrated risk

• Over moles, naevi or any pigmented lesion

That last point deserves emphasis. Never tattoo over a mole. The pigment prevents surveillance of that lesion and can delay a melanoma diagnosis by years. A good tattooist works around moles.

Is it normal for a tattoo to itch?

In the first few days, yes. Later, not always.

During healing — the first to second week — itching accompanies scabbing and skin regeneration. It is expected, and you should not scratch or pick off the scabs, or you will lose pigment and be left with patchy areas.

Itching that appears months or years later is a different matter. It can indicate a delayed allergic reaction to the pigment, more frequent with red inks, or a granulomatous reaction. It typically affects one specific colour in the design — the red becomes raised and itchy while the black beside it does not.

Persistent itching, raised areas, flaking or nodules in an old tattoo warrant dermatological assessment.

What not to do after getting a tattoo

• Do not pick scabs or scratch

• Do not expose it to sun during healing, and use sunscreen afterwards — UV degrades pigment and fades the design

• Do not immerse it in pools, sea, bath, sauna or jacuzzi for the first two to three weeks

• Do not wear tight clothing over the area

• Do not apply products with alcohol, fragrance or thick petrolatum

• Do not do intense exercise in the first few days, because of sweating and friction

• Do not drink alcohol in the first 24 hours, because of its effect on clotting

Warning signs requiring assessment: redness that increases rather than decreases after day three, growing pain, local heat, pus, fever, or red streaks spreading from the area.

Can I donate blood if I have a tattoo?

You can, but there is a temporary deferral period after getting tattooed.

The rule exists because of the theoretical risk of bloodborne infection during the procedure, not because of the ink. In Portugal the waiting period is set by the Instituto Português do Sangue e da Transplantação and should be confirmed with the service, as criteria are updated periodically.

After that period, and meeting the other criteria, donation is possible. Having tattoos does not prevent you from being a donor.

How to reduce the risks

The risk of a tattoo lies far more in the procedure than in the oncological hypothesis.

• A licensed studio with verifiable hygiene standards

• Disposable equipment, opened in front of you

• Inks compliant with European regulation — you can and should ask

• Avoid inks obtained outside legal channels or tattoos done in informal settings

• Never tattoo over moles

• Photograph the tattoo once healed, for future comparison

• Watch for changes: raised areas, persistent itching, nodules or colour change

If you have many tattoos and are having mole mapping, tell your dermatologist. Pigmentation makes dermoscopic assessment of lesions harder in and around tattooed areas.

When to see a dermatologist?

• When a tattoo becomes raised, itchy or flaky, months or years later

• When nodules or lumps appear in the design

• When there are enlarged lymph nodes in the area drained by the tattoo

• When a mole has been partly covered by pigment

• Before tattooing, if you have psoriasis, vitiligo, keloids or active skin disease

• For mole mapping, particularly with extensive tattooed areas

Dr Ellene Papazis is a dermatologist accredited in Portugal and Brazil, with training in cutaneous oncology, and performs mole mapping in Porto, Portugal.

Sources

• Nielsen C, et al. Tattoos as a risk factor for malignant lymphoma: a population-based case-control study. eClinicalMedicine, 2024. Lund University

• Regulation (EU) 2020/2081 — REACH restriction on substances in tattoo inks and permanent make-up

• European Academy of Dermatology and Venereology

• Instituto Português do Sangue e da Transplantação — donation criteria

Written and reviewed by Dr Ellene Papazis, dermatologist accredited in Portugal and Brazil. Consultations in Porto, Portugal.

Updated 25 July 2026.