Dengue: symptoms, warning signs and when to go to the hospital

Dengue symptoms usually start 4 to 10 days after a bite from an infected mosquito. Many people have mild symptoms or none at all. When dengue does make you sick, it can feel like flu at first.

The most common symptoms are:

• a sudden high fever, often around 40°C
• a strong headache
• pain behind the eyes
• muscle, joint and bone pains
• nausea or vomiting
• swollen glands
• a rash

The fever usually lasts 2 to 7 days. Most people recover within a week or two, but feeling tired can last for several weeks.

In babies and young children, dengue can be harder to recognize, because it can look like many other illnesses. Our guide on fever in babies and children explains the danger signs to look for in children.

Symptoms alone cannot prove that you have dengue, because many other infections also cause fever. A check-up and a blood test give the answer, so see a doctor early when you have a high fever, especially in the rainy season.

Dengue usually goes through three phases. Knowing them helps you watch closely at the right time.

1. Fever phase (about days 1 to 7). High fever, headache and body pains. Rest and drink plenty of fluids.
2. Critical phase (usually around days 3 to 7). This often starts just as the fever goes down, and it usually lasts 24 to 48 hours. In some people, fluid leaks out of the small blood vessels. Shock or serious bleeding can then follow within hours.
3. Recovery phase. Appetite comes back and strength slowly returns. Some people get a new rash that can itch or peel. This is common and usually harmless.

A falling fever does not always mean you are getting better. Warning signs usually appear in the day or two after the fever goes away. Keep watching during this time, even if you feel a little better. Keep drinking, and go to every check-up and blood test your doctor asks for.

Severe dengue is an emergency. If any warning sign appears, go to the hospital straight away. Don't wait for your next check-up. See when to get help now.

Many people with dengue can be cared for at home if they have no warning signs, can drink enough, and can get back to a doctor quickly. Your doctor may ask you to come back for check-ups and blood counts while you are sick.

Care in a hospital is needed for anyone with a warning sign. People at higher risk of severe dengue may need a hospital stay for closer watching, even before any warning sign appears:

• babies
• pregnant women
• older adults
• people with obesity, diabetes, high blood pressure, kidney, heart or lung disease, or another long-term illness
• people who live alone or far from a hospital

In the hospital, nurses and doctors check your blood pressure, pulse, urine and blood counts often, and give fluids through a drip (IV) when needed. Early, careful treatment saves lives: with timely care, very few people die of dengue.

Use our care finder to know where your nearest hospital is before you need it.

Blood tests help your doctor confirm dengue and see how your body is coping.

• NS1 rapid test. It finds part of the dengue virus in your blood and works best in the first 5 days of illness. Ask your doctor or health center where you can get it. A negative result does not always rule out dengue, so your doctor will still look at your symptoms.
• Antibody tests (IgM and IgG). These are more useful from about day 5 of illness.
• Complete blood count (CBC). It shows your platelets, which help your blood clot, and your hematocrit, which shows how thick or concentrated your blood is. Doctors often repeat it to see the trend.

Many people ask what platelet count is dangerous. No single number decides it. Doctors worry most when the platelet count falls quickly while the hematocrit rises, because this can mean fluid is leaking from the blood vessels. Warning signs matter as much as the numbers: if you have a warning sign, go to the hospital even if your last platelet count looked fine.

A CBC is one of the lab tests covered by PhilHealth YAKAP when your YAKAP doctor orders it.

Dengue is caused by a virus. It spreads through the bite of an infected Aedes mosquito, mostly Aedes aegypti. They bite mostly during the day. They lay their eggs in containers that hold water, such as water drums, pails, flower vases, plant pots, old tires and pet bowls.

There are four types of dengue virus. After you recover, you are protected against the type you had, but not against the other three. A second infection with a different type carries a higher risk of severe dengue.

Dengue is not spread through touch, coughing or sharing food. It spreads mainly through mosquito bites, and rarely from a pregnant woman to her baby or through a blood transfusion. A mosquito that bites a sick person, from about 2 days before the fever starts until about 2 days after it ends, can carry the virus to others. While you have a fever, sleep under a mosquito net or in a room with screens so you don't pass dengue on to your family.

In the Philippines, dengue cases usually rise in the rainy season, when more water collects in containers around homes.

There is no medicine that kills the dengue virus. Care helps your body get through the illness while doctors watch for warning signs.

What helps

• Rest as much as you can.
• Drink plenty of fluids: water, oral rehydration solution (ORS, often called oresol), soups and other drinks. Drinking enough is one of the most important things you can do.
• Paracetamol for fever and body pain, taken exactly as the label says. Taking more than the label allows can harm the liver, so ask a pharmacist or doctor first if you have liver disease.
• Watch how much you pee. Peeing much less than usual can mean you need more fluids or need to be checked.

What to avoid

• Ibuprofen, aspirin, mefenamic acid and other NSAID pain relievers. They can make bleeding more likely in dengue. Check the label of any pain, fever or flu medicine for these ingredients, and ask your pharmacist if you are not sure.
• Antibiotics, unless a doctor finds a bacterial infection. Dengue is caused by a virus, and antibiotics do not work against viruses.
• Herbal remedies in place of care. Tawa-tawa, papaya leaf juice and other remedies have not been proven to treat dengue, and PhilHealth's dengue care standards do not recommend herbal medicines. Never let them replace fluids, check-ups or blood tests.

Not sure whether a medicine is safe with dengue? Ask our free AI symptom guide or ask a nurse.

Money should not stop you from getting checked for dengue:

• PhilHealth YAKAP covers free consultations and a CBC at your registered YAKAP clinic, which can be your health center or rural health unit (RHU) (see our PhilHealth YAKAP guide).
• PhilHealth pays for hospital care for dengue. As of late 2026, PhilHealth pays ₱19,500 for a hospital stay for dengue with or without warning signs, and ₱47,000 for severe dengue. Under the Universal Health Care law, every Filipino is a PhilHealth member.
• In a basic (ward) bed, PhilHealth's rules say accredited public and private hospitals should not charge you a co-payment for dengue care. A private room or extra services can cost extra.
• Malasakit Centers in government hospitals give medical and financial help to patients who cannot afford their bills.

Our free care navigator can help you find out what you can get for free near you.

The DOH asks every household to do the 4S against dengue:

1. Search and destroy mosquito breeding places. Regularly empty and scrub water containers and cover them, change the water in flower vases, turn over (taob) unused pails and cans, and clear blocked gutters.
2. Self-protection. Use mosquito repellent, wear long sleeves and long pants, and use window screens and mosquito nets, especially for babies and people who are sick.
3. Seek early consultation. See a doctor or go to your health center early when you have a fever, especially in the rainy season.
4. Say yes to fogging only during outbreaks. Fogging alone does not stop dengue: getting rid of breeding places matters most.

As of mid-2026, the FDA Philippines said the dengue vaccine Qdenga was not yet registered in the country, and it warned the public about fake Qdenga vaccines being sold. Do not buy vaccines online or from unlicensed sellers. Ask your health center for the latest advice.