Nine Pints summary

Try not to shudder – we’re going to talk about leeches. These little critters are almost universally despised by humankind, who view them as slimy little parasites. But while leeches might not be the most glamorous creatures in the animal kingdom, they have played a central role in medical care for centuries.

Throughout most of our history, the leech has been prized for its bloodsucking ability.

Few women have had a bigger impact on British medical care than Dame Janet Vaughan.

Born in 1899, Vaughan fought to receive an education when educated women were frowned upon, studying medical sciences at the University of Oxford and graduating with distinction. While at Oxford, she also first encountered her lifelong passion: the research of blood. 

We popularly think of plasma as a futuristic energy source in far-fetched science fiction universes. But there’s plasma closer to home that’s just as impressive – in fact, it’s flowing through your veins right now. Plasma makes up over half of your blood’s volume and consists of fat, water, salt, proteins, antibodies and coagulants that help clot the blood.

There are several ways we can harvest plasma for medicinal purposes. First, it can be separated from blood after a donation, yielding fresh frozen plasma (FFP). FFP transfusions are normally used to encourage blood clotting.

For a process so natural, it’s incredible that discussing menstruation still elicits embarrassment, silence or outright disgust. This extends to politics in the UK, where activists have campaigned for years to classify female sanitary products as a necessity, which would exempt them from tax. In many developing countries, the issues are far more serious and ingrained. 

In Nepal, for instance, there’s the practice of chaupadi. It involves physically isolating menstruating women from their families, forcing them to sleep in tiny, dirty outhouses. 

AIDS is a syndrome characterized by a malfunctioning immune system, dangerously lowering the body’s defenses – and it’s caused by HIV. To understand both HIV and AIDS, we need to understand the blood, particularly, CD4 white blood cells. 

These cells are extremely important to our immune system, recognizing threats to the body and releasing chemicals that attract other white blood cells to the danger zone. CD4 cells are like air traffic controllers, guiding white blood cells to their destination.

Trauma is a shortened term for traumatic injury – sudden, severe physical damage requiring immediate treatment. Although it’s mentioned less frequently than cancer or HIV, trauma is still the cause of 10 percent of deaths worldwide. Of these, 40 percent die from severe bleeding.

How does this happen, if our blood is supposed to clot?