Cancer is a large group of diseases that can start in almost any organ or tissue of the body when abnormal cells grow uncontrollably, and go beyond their usual boundaries to invade adjoining parts of the body. According to the World Health Organization (WHO), it is the second most common cause of death globally, accounting for millions of deaths every year. Lung, prostate, colorectal, stomach and liver cancer are the most common types of cancer in men, while breast, colorectal, lung, cervical and thyroid cancer are the most common among women. However, these are not necessarily the deadliest forms of cancer.

What makes cancer the deadliest depends upon how many people have it and what percentage of those people actually survive. Cancer researchers determine this on the basis of five-year relative survival. This is the percentage of people who are expected to survive the effects of a given cancer, excluding their risk of other possible causes of death, for five years past a diagnosis. It is also important to note that what makes cancer really deadly is that practically no cure for it. A cure for cancer would imply that there are no cancerous cells remaining in the body.

Here are the 5 deadliest cancers in the U.S., according to SEER five-year relative survival data for cases diagnosed between 2014 and 2020.

1. Pancreatic cancer occurs when cells in your pancreas, a gland in your abdomen that aids digestion, mutate and multiply out of control, forming a tumour. Major risk factors include smoking, obesity, diabetes, chronic pancreatitis, certain genetic mutations and environmental chemical exposure.

2. Esophageal cancer develops in the oesophagus, which is the tube that connects your throat to your stomach.

3. Liver cancer and intrahepatic bile duct cancer originate in the liver or bile ducts, often linked to hepatitis infections, heavy alcohol use, obesity, and aflatoxin exposure.

4. Lung and bronchus cancer primarily caused by smoking, secondhand smoke, and environmental pollutants, affects the lungs and airways, making it the leading cause of cancer death in the US.

5. Acute myeloid leukaemia (AML) is an aggressive blood and bone marrow cancer that progresses rapidly, often linked to genetic mutations, radiation exposure, and certain chemicals.

ALSO READ: Why Are Lifestyle Factors Making Millennials Vulnerable To Cancer?

For the past two days, Delhi locals have been waking up to extreme heatwave conditions. The India Meteorological Department (IMD) issued a warning of an extreme heatwave for Friday and Saturday, and we are now on day 2. On Friday, temperatures in the national capital were recorded at 43.1 degrees Celsius and 41.9 degrees Celsius. At the Ridge station and Lodhi Road, a high of 41.8 degrees was recorded, which met the criteria for heatwave conditions. Citing this, the IMD issued a yellow alert for Saturday, forecasting isolated heatwave conditions in the city. With this comes an increased risk of heat stress.

What is heat stress?

Heat stress refers to a state wherein the body absorbs more heat from the environment or produces heat through exertion that overwhelms the body's natural cooling system. This is caused by humidity, high temperatures, or exercise, leading to symptoms like headaches, dizziness, and, in extreme cases, heatstroke.

Heat stress occurs when the body is exposed to radiant heat, high air temperature, physical exertion, high humidity, or low air movement. It harms the body's ability to maintain a normal core temperature, thereby resulting in dehydration and cardiovascular strain. It is advised to wear protective clothing and drink plenty of water to stay hydrated.

What are the signs of heat stress?

Dr Anirban Chattopadhyay, Senior Consultant, Critical Care Medicine, CK Birla Hospitals, CMRI, in an interaction with Health and Me, spoke about the symptoms of heat stress. The expert said, “As the summer season begins and the sunlight is now scorching, heat and related symptoms increase. One of the early symptoms of heat exhaustion is headache, light-headedness, dizziness, and brain fog. This happens because the brain is temperature-sensitive. That is why patients often experience a headache when temperatures rise. This occurs due to vasoconstriction. One may experience dizziness and brain fog because the brain cannot withstand high levels of heat. These are the early symptoms of heat stress.”

When heat stress or prolonged heat exposure continues, it can progress to a more serious condition. This may even lead to a comatose state, known as heatstroke. Therefore, avoid direct sunlight exposure. If possible, stay indoors during peak hours, from 12 pm to 3 pm. Drink plenty of water to keep yourself hydrated, and consume electrolyte-containing fluids to maintain balance. When going out, use umbrellas and sunglasses, and wear breathable fabrics like cotton.

Heatwave across Central and North India

The heatwave is not restricted to the national capital—it is currently affecting northern and central states such as Madhya Pradesh, Rajasthan, Bihar, Chhattisgarh, Chandigarh, and Haryana. The conditions are likely to continue until April 27, with low chances of relief in the coming week.

World Malaria Day is observed on April 25 every year - on this day, experts spread awareness about malaria, an infection caused by the bite of the female Anopheles mosquito. Its symptoms include extremely high fever, headaches, chills, and fatigue. However, ahead of or during the monsoon season, people often get confused between viral fever and malaria due to similar symptoms. As a result, the infection is diagnosed late. On this occasion, Health and Me interacted with experts to learn more about the tests that one must take for malaria diagnosis.

An increase in the number of patients presenting at diagnostic centres with very high fevers has been attributed to people assuming they have a seasonal virus; however, when these patients present later, they often have life-threatening complications. According to the World Health Organization, over 280 million cases of viral infections worldwide were reported last year, making the clinical distinction between malaria and viral diseases increasingly deceptive.

Which tests to take for malaria diagnosis?

Dr Divya C, Microbiologist at Neuberg Anand Reference Laboratory, said, “Diagnostic testing has also transformed from the traditional microscope to more advanced diagnostic techniques, such as dual-target RDT (rapid diagnostic test), which detects HRP2 and Pf-LDH antigens. The RDT may not be able to detect some infections with lower numbers of malaria parasites circulating in the patient’s bloodstream. Therefore, all negative RDTs must be followed by microscopy to confirm the result.”

The expert went on to say that molecular PCR tests are now the preferred tests for cases with low parasite density or asymptomatic carriers, as they can detect fewer than 10 parasites per microlitre of blood with high levels of sensitivity. Some leading laboratories that perform PCR testing are also including AI-assisted digital microscopy as a supplement to the process, reducing human fatigue and providing significantly more precise results than a manual smear could.

What happens when malaria is diagnosed late?

The risk of “waiting to see” if malaria develops after the initial temperature spike is that, unlike most other viral fevers, malaria infects human red blood cells; the consequence of waiting can be organ failure or cerebral complications within 48–72 hours after the initial symptomatic temperature spike.

It is recommended that any patient with cyclic chills, excessive sweating, or fatigue should be tested based on differential diagnosis, as India moves towards becoming malaria-free by 2027. There is a short 15-minute diagnostic window to determine whether a patient can be treated without complications or is at risk of dying from malaria if it is missed.

Dr Praveen K Bharti (Scientist G), Director, ICMR–National Institute of Research in Tribal Health (NIRTH), Jabalpur, said, “We need testing to catch malaria early, but we also need the right kind of tests. Traditional tests often miss low-density, mixed, and asymptomatic infections. These are not minor gaps. As India advances towards its malaria elimination goals by 2030, point-of-care molecular tests for malaria diagnosis that can detect low-density, hidden reservoirs of infection will prove to be the key differentiator.”

Every year on 25 April, World Malaria Day is observed to raise awareness about one of the deadliest yet preventable diseases.

According to the latest World Malaria Report 2025, there were 282 million cases of malaria in 2024, an increase of about 9 million cases (3 per cent) compared with 2023.

The estimated number of malaria deaths stood at 610,000 in 2024 compared to 598,000 in 2023.

With 37 countries reporting fewer than 1,000 cases in 2024, progress at the global level is stalling.

World Malaria Day 2026: Theme

The theme this year is "Driven to End Malaria: Now We Can. Now We Must."

According to the World Health Organization, for the first time, ending malaria seems to be a real possibility, as science is advancing faster than ever with new vaccines, treatments, malaria control tools and pioneering technologies.

That is why the theme "is a rallying cry to grasp the moment—to protect lives now and fund a malaria-free future".

The theme also builds on a strong line of focused global campaigns in recent years that resulted in 47 countries being certified malaria-free.

In the last few years, substantial progress has been made, with an estimated 2.3 billion malaria infections prevented and 14 million lives saved worldwide since 2000.

However, the WHO flagged that the gains are at risk due to multiple challenges, including

• drug resistance,
• insecticide resistance,
• diagnostic failure,
• severe reductions in funds.

The theme also underscores the need to end Malaria by 2030 with coordinated global action. As stronger community health systems have brought the world closer to this goal than ever before, the day presents the need to boost

• Advances in malaria vaccines,
• Improving diagnostic tools,
• Develop more effective treatments.

World Malaria Day: History

World Malaria Day was first celebrated internationally in 2008, building upon the earlier "Africa Malaria Day", which had been observed by African countries since 2001. The date, April 25, was established by the WHO in 2007 during the World Health Assembly.

In 2007, it was the 60th session of the World Health Assembly where the proposal to rename Africa Malaria Day to World Malaria Day was made to acknowledge the global presence of malaria.

Read: Thought A Heatwave Could Save You From Malaria? Expert Begs To Differ

World Malaria Day: Significance

The day has a strong significance in healthcare as it brings attention to the disease that still continues to take so many lives, especially in low-income and tropical regions. It also serves as an important reminder to continue spreading awareness about the disease as well as promoting its prevention, treatment, and continuous international cooperation to fight against it.

What Is Malaria?

The WHO describes malaria as a life-threatening disease spread to humans by some types of mosquitoes, mostly found in tropical countries. However, they are preventable and curable.

"Malaria is spread to people through the bites of some infected anopheles mosquitoes. Blood transfusion and contaminated needles may also transmit malaria," as per the WHO.

The first symptoms may be mild, similar to many febrile illnesses, and difficult to recognize as malaria. Left untreated, P. falciparum malaria can progress to severe illness and death within 24 hours.

The WHO notes 5 Plasmodium parasite species that cause malaria in humans.

• P. falciparum — the deadliest malaria parasite and the most prevalent on the African continent.
• P. vivax — the dominant malaria parasite in most countries outside of sub-Saharan Africa.

• P. malariae,
• P. ovale
• P. knowlesi.

Symptoms of Malaria

The early symptoms include fever, headache, and chills, which can usually start within 10 to 15 days of getting bitten by an infected mosquito.

Some types of malaria can cause severe illness and death. Infants, children under 5 years, pregnant women, travellers, and people with HIV or AIDS are at higher risk. Severe symptoms include:

• extreme tiredness and fatigue
• impaired consciousness
• multiple convulsions
• difficulty breathing
• dark or bloody urine
• jaundice (yellowing of the eyes and skin)
• abnormal bleeding.