Do you know who can donate blood to you or who can you donate blood to? Blood donation may not be complex, but it does need to be compatible with yours and vice-versa. The blood types are determined by the presence or absence of certain antigens - substance that can trigger immune response if they are foreign to the body.

There are four major blood groups which are determined by the presence or absence of two antigens, A and B, on the surface of red blood cells. There is also a protein called the Rh factor, which can either be present (+) or absent (-), which creates A+, A-, B+, B-, O+. O-, AB+, AB- blood types.

Group A blood type has only A antigens on red blood cells and B antibody in the plasma. B has only B antigen on red cells and A antibody in the plasma. AB has both A and antigens on red cells, but neither A nor B antibody is present in the plasma. O has neither A nor B antigens on red cells, but both A and B antibody are present in the plasma.

Blood Type And Who Can You Donate To?

Your blood type determines who can you donate to. This is because there are very specific ways in which blood types must be matched for safe transfusion. The right blood transfusion could actually save you, while the wrong one could be lethal. Also, Rh-negative blood is given to Rh-negative patients and Rh-positive or Rh-negative blood can only be given to Rh-positive patients.

If you are O blood type, you can donate to O, A, B, and AB, if you are A blood type, you can donate to A and AB, if you are B blood type, you can donate to B and AB, however if you are AB, you can only donate to AB.

Who Can You Receive Blood From?

If you are O blood type, you can only receive from O. If you are A, you can receive from type A and O. If you are blood type B, you can receive from type B and O. If you are AB, you are lucky, you can receive blood from O, A, B, and AB.

There are more than 600 other known antigens, the presence or absence of which creates "rare blood types". Certain types are unique to specific ethnic or racial groups, this is why an African-American blood donation can be the best hope for the needs of patients with sickle cell disease, as per the Red Cross Organization.

Universal Blood Donor

Type O is one in high demand, as it can donate blood to anyone. O negative blood type is the universal blood type, which can donate to everyone, especially during the emergency transfusions and for immune deficient infants.

Who Have These Blood Types In US?

In the US, 37% Caucasian, 47% African-American, 39% Asians, and 53% Latino-American are O-positive. However, only 8% of Caucasian, 4% of African-American, 1% Asian, and 4% Latino=Americans are O-negative.

A+: 33% Caucasian, 34% African-American, 27% Asian, 29% Latino-American

A-: 7% Caucasian, 2% African-American, .5% Asian, 2% Latino-American

B+: 9% Caucasian, 18% African-American, 25% Asian, 9% Latino-American

B-: 2% Caucasian, 2% African-American, .4% Asian, 1% Latino-American

AB+:3% Caucasian, 4% African-American, 7% Asian, 2% Latino-American

AB-: 1% Caucasian, .3% African-American, .1% Asian, .2% Latino-American

As the 2026-27 flu season begins in the US, doctors are reminding people that influenza can cause more than just cough, fever and a runny nose. Symptoms can come on suddenly and affect the entire body, with some patients also developing gastrointestinal symptoms.

During the 2025-2026 flu season, influenza caused at least 32 million illnesses, 390,000 hospitalizations and 24,000 deaths in the US, according to preliminary data from the Centers for Disease Control and Prevention (CDC).

According to the World Health Organization, from February through August 2026, influenza A(H1N1)pdm09, A(H3N2) and influenza B viruses circulated across regions. Influenza A viruses predominated in most regions, while influenza B dominated in Northern and Western Africa, North America and Eastern Asia.

While it is too early to know what the season ahead will look like, knowing the range of flu symptoms can help people recognize the infection. These include the classic symptoms of sudden fever, chills, body aches and extreme fatigue, as well as vomiting and diarrhea in some children.

Flu Symptoms Can Come On Suddenly

Also read: WHO Sets 2027 Flu Vaccine Strains; US States Can Now Order Free COVID Shots For Kids

Influenza commonly affects the nose, throat and lungs, but its symptoms can be widespread.

The most common symptoms include:

• Fever

• Chills

• Body aches

• Extreme fatigue

• Headache

• Sore throat

• Runny or stuffy nose

• Cough

Family physician Carlos Galindo at Texas Health Family Care said fever, chills and body aches are the classic flu combination. People may also develop a sore throat, runny nose and headache, according to the American Medical Association.

Unlike the gradual tiredness that can accompany a cold, flu-related fatigue can be intense.

Galindo described it as significant lethargy and malaise, with some patients feeling completely drained.

Watch For Severe Body Aches And Fatigue

One of the key features doctors want people to recognize is how quickly influenza can make someone feel unwell.

Family physician Christopher Zipp of Atlantic Health in Morristown, New Jersey, said flu symptoms can develop over just a few hours, with fever, chills and body aches appearing suddenly.

However, flu symptoms can overlap with those of other respiratory infections, so symptoms alone cannot always confirm that someone has influenza.

Read More: Fall Vaccines 2026: US Doctors Issue COVID, Flu And RSV Jab Guidance

Children Can Have Vomiting And Diarrhea

Flu symptoms can also differ between children and adults. While fever, chills, body aches and respiratory symptoms are common, children may also develop gastrointestinal symptoms such as vomiting and diarrhea.

These symptoms can occur alongside cough, sore throat or other signs of respiratory infection.

When Can Flu Become Serious?

For most people, influenza is an unpleasant but temporary illness. However, it can sometimes lead to complications such as pneumonia and hospitalization, particularly in people with underlying health conditions.

Symptoms that become severe or worsen rather than improve warrant medical attention, especially among people at higher risk of complications.

In the US, many flu cases are seen between January and March, although influenza can circulate outside the peak season as well.

Doctors generally recommend flu vaccination around September or October to build protection before activity increases. It takes about two weeks for the body to develop protection after vaccination. Flu vaccination has been shown to reduce flu-related doctor visits by about 40% to 60%.

A mammogram is routinely used to detect early signs of breast cancer, but the imaging test may also provide clues about a woman’s cardiovascular health.

Cardiovascular disease is a major cause of death among women. Yet, experts say heart disease in women can be overlooked because symptoms and risk factors may differ from the patterns traditionally associated with men.

Why Heart Disease Can Be Missed In Women

Prof Rob Galloway of University Hospitals Sussex NHS Foundation Trust, writing in the Daily Mail, highlighted the need to identify cardiovascular disease in women earlier.

Citing a 2021 The Lancet study, he noted that women with cardiovascular disease remain “understudied, under-recognized, underdiagnosed, and undertreated.”

Galloway said he regularly sees women, particularly those in their 60s, arriving in emergency care with heart attacks after earlier symptoms were attributed to less serious causes.

“If that had been recognized, she could have been admitted, and if needed, had a stent (a mesh tube) inserted to open the artery before it was blocked,” he wrote.

“The truth is doctors are not as good as we should be at recognizing heart disease in women, or understanding their risk,” he added.

Also read: New Breast Cancer Guidelines Recommend Mammograms Every Two Years for Women

Heart Attack Symptoms May Look Different In Women

Women may experience heart attacks differently, with symptoms such as breathlessness, nausea, fatigue, or back, neck and jaw pain. Galloway also highlighted female-specific risk factors, which include:

• Preeclampsia or high blood pressure during pregnancy
• Gestational diabetes
• Premature menopause
• Polycystic ovary syndrome (PCOS)

He said these factors are not always routinely included when assessing a woman’s long-term cardiovascular risk.

What Can A Mammogram Reveal About Heart Risk?

Read More: World Heart Day: You Feel Healthy. But Plaque May Already Be Building In Your Arteries In Your 20s

Prof Galloway suggested that routine breast screening could potentially offer another opportunity to identify cardiovascular risk.

When blood vessels are damaged, calcium can accumulate in their walls. Mammograms can sometimes detect calcium deposits in the arteries of the breast, known as breast arterial calcification (BAC).

BAC is different from calcium buildup in the coronary arteries, but its presence has been associated with a higher risk of cardiovascular events such as heart attack and stroke. Some radiologists may therefore flag the finding to the treating doctor.

Could AI Detect Heart Risk From Mammograms?

Prof Galloway also discussed the potential role of artificial intelligence in identifying and measuring breast arterial calcification.

A European Heart Journal study used AI to assess mammograms from over 123,500 US women. Compared with no calcification, mild breast arterial calcification was linked to a 30% higher cardiovascular event risk, moderate to 75–80% higher risk, and severe to roughly three times higher risk.

The association persisted even after researchers accounted for established cardiovascular risk factors such as obesity and smoking.

Could Mammograms Become A Cardiovascular Screening Tool?

Prof Galloway said that the potential advantage is that the mammogram has already been performed for breast screening. If arterial calcification is identified, that information could potentially be included with the screening result and prompt a broader cardiovascular risk assessment.

Depending on the woman's overall risk, doctors could then consider measures such as more intensive management of blood pressure or cholesterol.

A coronary artery calcium scan is another way to assess calcium buildup in the arteries supplying the heart. It uses a CT scan to detect and measure coronary artery calcium and can help inform cardiovascular risk assessment in appropriate patients.

One may dismiss a recurring ache in the calf or thigh while walking may as a muscle problem, especially if it settles after sitting or resting. But leg pain that repeatedly appears while walking and eases after resting can sometimes be due to a circulation problem called peripheral artery disease (PAD).

The condition occurs when arteries that carry blood to the legs become narrow, usually because of atherosclerosis, which is the buildup of fatty deposits inside blood vessels. PAD can be a major sign that the same process is also affecting arteries in the heart and brain, signalling a major cardiovascular risk.

Women May Overlook The Symptoms

PAD can be difficult to identify as it comes with ordinary symptoms that could be tied to ageing or injury.

Women may neglect it as they may experience less obvious symptoms, including leg fatigue or weakness rather than cramping. This is because the condition is affected by ageing, fitness, or a musculoskeletal issue.

Apart from pain during walking, possible symptoms include:

• Coldness in one foot or leg
• Numbness or weakness
• Changes in the colour of the skin
• Shiny skin or loss of hair on the legs
• Slow-growing toenails
• Sores on the feet or legs that heal slowly
• Pain in the feet or toes, particularly at rest in more advanced disease

Some people may have no noticeable symptoms, which can allow PAD to progress without being recognised, leading to serious complications.

Also read: Pomegranate Compound Improves Heart Function By Up To 80% In Early Heart Failure Study

Canada Is Focusing On PAD

The disease has prompted a new Canadian National Action Plan for Peripheral Artery Disease, developed by vascular medicine experts with the Canadian Society of Vascular Medicine and Prevention.

The plan calls for greater public awareness, early diagnosis, better access to ankle-pressure testing, supervised exercise programmes and specialised care for people with PAD.

The Canadian authors also said that PAD can be difficult to diagnose in rural and remote communities and among Indigenous Peoples and other underprivileged populations, where access to preventive care and vascular specialists may be limited.

Delayed diagnosis can mean that people are only identified after complications like non-healing wounds or in severe cases, amputation.

Also read: 100% Blockage At 18, 25% Patients Under 40: On World Heart Day, Cardiologists Reveal An Alarming Heart Attack Pattern

PAD Is Linked To Heart Attack And Stroke

PAD happens when narrow and blocked arteries reduce the blood flow to the legs. When the muscles need more oxygen during walking or exercise, the reduced circulation can lead to uncomfortable pain.

This symptom is called intermittent claudication. The pain usually develops in the calf, thigh or buttocks while walking. It subsides or improves after sitting down or resting the legs.

But not everyone experiences this symptom. Some may instead face tiredness in the legs, weakness, numbness or just discomfort, making it easier to dismiss the symptom.

The arteries in the legs are not isolated from the rest of the circulatory system. PAD is usually caused due to atherosclerosis, the same underlying process that could lead to thinner arteries supplying blood to the heart and brain.

As a result, having PAD can indicate a higher risk of heart attack, stroke and other cardiovascular complications. PAD risk increases with age, but several other lifestyle factors can contribute. These include:

• Smoking
• Diabetes
• High blood pressure
• High cholesterol
• Family history of vascular disease

Diabetes is most likely to contribute to PAD because persistently high blood sugar can damage blood vessels and increase the risk of atherosclerosis.

When To Seek Medical Intervention?

If leg pain or unusual tiredness keeps interrupting your life, it is worth getting evaluated, particularly if you have diabetes, smoke or have high blood pressure or cholesterol.

Doctors may assess circulation using an ankle-brachial index (ABI), which compares blood pressure in the ankle with blood pressure in the arm.

Treatment may include lifestyle changes like increasing physical activity, quitting smoking and medicines to manage cholesterol, blood pressure, and blood clotting risk. Severe blockages may also require medical procedures.