VisitDoctorJapan

Fever (Adults) in Japan: What to do (and when to call 119)

Fever (Adults) in Japan: What to do (and when to call 119)

Last updated: 2026-03-03

TL;DR (30-second decision)

  • Note for parents: This page is for adults. Fever management is different for children, and some common adult OTC medicines (including many NSAIDs) are not appropriate for kids. For child fever guidance (including when to call #8000 or 119), see: Fever (Children) in Japan
  • Call 119 now if you have trouble breathing, severe chest pain, confusion, fainting, severe weakness, or you feel seriously unwell.
  • If it’s not clearly urgent: rest + fluids, and consider a fever reducer for comfort.
  • In Japan, if you have fever or cold-like symptoms, many clinics ask you to call ahead before visiting. Bring a mask.

When to call 119 (red flags)

Call 119 immediately if you have any of the following:

  • Trouble breathing, lips turning blue, or severe wheezing
  • Severe chest pain
  • New confusion, severe drowsiness, fainting
  • Seizure
  • Signs of stroke (face drooping, arm weakness, speech difficulty)
  • Severe dehydration (cannot keep fluids down, very little urine)
  • You feel your condition is rapidly worsening

(This page is general guidance, not a medical diagnosis.)

What you can do right now at home

  • Hydrate: small sips frequently (water, oral rehydration drinks).
  • Rest and keep the room comfortably cool.
  • Check your temperature and note when the fever started.
  • Avoid alcohol and avoid intense exercise until you recover.

OTC fever medicines in Japan (adult)

Important (children): This page is for adults. For children, dosing and safe medicines are different. Please use the children’s guide: Fever (Children) in Japan.

In Japan, the most common OTC options are acetaminophen (paracetamol) and NSAIDs (such as ibuprofen or loxoprofen). Choose one, follow the package directions, and avoid combining multiple products that contain the same ingredient.

Option A: Acetaminophen (paracetamol)

  • Often a good first choice for fever when you mainly want to lower temperature and ease aches.
  • Do not exceed the maximum daily dose written on the label, and avoid taking multiple cold/flu products that also contain acetaminophen.

Option B: NSAIDs (ibuprofen / loxoprofen, etc.) — use with extra caution

NSAIDs reduce fever and inflammation, but they can also mask the signs of infection and may affect immune responses—so if you suspect a bacterial infection or your symptoms are getting worse, don’t use NSAIDs to “push through”; consider medical evaluation instead.

Avoid NSAIDs or ask a pharmacist/doctor first if you have a history of stomach ulcers/bleeding, kidney disease, are taking blood thinners, have uncontrolled high blood pressure, or are pregnant.

Important Japan-specific note: Loxonin is OTC, but it’s “Class 1”

Loxonin S (loxoprofen) is a very common OTC pain/fever medicine in Japan. However, it is a Class 1 OTC drug (Daiichi-rui Iyakuhin), meaning it is sold under stricter rules and typically involves pharmacist involvement/information provision at purchase.

Practical tip: If you want loxoprofen, go to a drugstore when a pharmacist is available, and be ready to answer quick questions (age, symptoms, other meds, allergies).

When you should see a doctor (even if it’s not “119” urgent)

Consider medical care if:

  • Fever lasts 3+ days, or keeps coming back
  • Fever is very high or you feel extremely unwell
  • You have severe sore throat, shortness of breath, chest pain, severe headache/stiff neck, rash, or persistent vomiting
  • You are immunocompromised, have serious chronic disease, or recently traveled with unusual exposures

How to visit a clinic/hospital in Japan when you have fever

This matters a lot:

  • If you have fever/cold-like symptoms, many clinics will ask you to call ahead to confirm they can see you and to follow infection-control instructions.
  • Some facilities may ask you to wait outside or in your car, use a separate entrance, or follow special procedures.
  • Bring a mask—many clinics/hospitals request it.

What to say (simple English)

Calling a clinic

“Hello. I have a fever and [cough/sore throat].
My temperature is [38.5]°C and it started [yesterday].
Can I visit today? Do I need an appointment?”

At reception

“I have a fever. These are my symptoms.”
“I can wait outside if needed.”

FAQ

Can I buy fever medicine without a prescription in Japan?

Yes—many fever/pain medicines are available OTC. Some products (including Loxonin S) are Class 1 OTC, so a pharmacist may be involved at purchase.

Is it OK to use NSAIDs when I might have an infection?

Be careful. NSAIDs can reduce fever and pain, but they may mask signs of bacterial infection and affect immune responses. If symptoms are worsening or severe, seek medical evaluation instead of repeatedly taking NSAIDs.

Do I need to make an appointment if I have a fever?

Often, yes. Many clinics ask you to call ahead for fever/cold symptoms and follow their instructions.

Should I wear a mask when I go to a clinic/hospital in Japan?

In many places, yes—mask-wearing is commonly requested in medical facilities. Bring one with you.

Related pages