What Blood Tests Should I Get?
A calm guide to choosing the right health tests for you
Understanding your health through blood testing can feel incredibly empowering. But for many people, the first question is simply:
"Which tests should I actually have?"
The answer depends on why you are testing in the first place.
Some people are exploring symptoms such as fatigue or hormonal changes. Others want reassurance that their health markers look good. Many simply want a clearer baseline so they can understand how their body is functioning now — and how it changes over time.
At Cocoon, we believe testing should feel clear, thoughtful and purposeful, rather than overwhelming.
This guide explains how to think about blood testing in a way that supports both understanding and long-term wellbeing.
If you want a general health overview
For many people, the best place to begin is a baseline health panel.
This type of test looks at a broad selection of biomarkers associated with overall wellbeing, including:
- Nutrient levels
- Metabolic health
- Hormone balance
- Thyroid function
The purpose is not to search for illness, but to understand how key systems in the body are functioning.
Markers such as cholesterol and HbA1c can provide insight into cardiovascular and metabolic health. Nutrient markers such as vitamin D, vitamin B12 and ferritin can highlight deficiencies that may influence energy, immunity and resilience.
The NHS notes that high cholesterol and other metabolic changes often cause no symptoms, which is why they are typically identified through blood tests rather than physical signs.
If you feel tired all the time
Fatigue is one of the most common reasons people explore blood testing.
Persistent tiredness can be influenced by many factors, including:
- Iron deficiency
- Vitamin B12 deficiency
- Low vitamin D
- Thyroid imbalance
- Metabolic changes
Testing these markers can help clarify whether a biological factor may be contributing to low energy.
At Cocoon, our Tired All the Time test focuses on biomarkers commonly associated with fatigue so that individuals can better understand what may be affecting their energy levels.
If you want to understand your hormones
Hormonal testing can be helpful for people experiencing changes in energy, mood, sleep or reproductive health.
Important hormones often assessed include:
- Testosterone
- Oestradiol
- Progesterone
- Thyroid hormones
Hormone levels naturally shift over time, and testing can provide a clearer picture of whether changes in how you feel may be linked to biological patterns.
If you are focused on fitness or performance
Athletes and active individuals sometimes use blood testing to understand factors that may influence recovery and endurance.
Markers such as ferritin (iron stores), vitamin D and B12 can affect muscle function, oxygen transport and energy metabolism.
The UK Sports Institute notes that vitamin D is important for bone and muscle health and that supplementation may be guided by blood testing.
Testing therefore allows training decisions to be informed by physiology, rather than guesswork.
If you are planning for fertility
Fertility is influenced by a combination of hormonal balance, nutrient status and overall health.
Blood testing can provide insight into markers such as:
- Reproductive hormones
- Thyroid function
- Vitamin D
- Folate and B12
- Iron status
The NHS explains that hormone blood tests are commonly used when investigating fertility concerns.
Understanding these markers early can sometimes provide helpful context when planning for pregnancy.
The Cocoon perspective
Choosing the right blood test should feel straightforward.
Rather than trying to measure everything at once, the most helpful approach is usually to begin with a clear question:
- How is my overall health?
- Why am I feeling this way?
- What is happening with my hormones?
- How can I optimise my performance?
From there, testing becomes much easier to navigate.
At Cocoon, our aim is always to help people understand their biology with confidence — combining scientific insight with a calm, supportive approach to care.