Longevity Hub › Genetic
Genetic Testing for Health: The Complete Guide
Your DNA shapes how your body processes food, responds to exercise and medication, manages stress, and ages. Genetic testing reads that blueprint to help you understand your health and make more personalised choices, instead of guessing. This guide covers what a DNA test can actually tell you, how it works, the different types available, and how to make sense of your results.
On this page
- 1.What can a DNA test tell you about your health?
- 2.How does genetic health testing work?
- 3.What are the different types of genetic tests?
- 4.Can your genes predict disease?
- 5.How do your genes affect what you should eat? (nutrigenomics)
- 6.How do your genes affect medication? (pharmacogenomics)
- 7.Is genetic testing worth it?
- 8.How do you make sense of your results?
- 9.Questions
What can a DNA test tell you about your health?
A health DNA test can reveal how your body is genetically set up across many areas. A comprehensive test typically covers:
- Disease susceptibility: Variants that may raise or lower your likelihood of certain conditions
- Nutrition and metabolism: How you process nutrients, caffeine, fats, and respond to different diets
- Medication response: How your body may react to common medications (pharmacogenomics)
- Fitness and recovery: Your tendencies for strength, endurance, and injury risk
- Longevity and ageing: Genes involved in cellular repair and how your body ages
- Mind and mood: Genetic influences on focus, memory, and stress
The point isn't to predict your future, it's to understand your tendencies so you can act on them.
How does genetic health testing work?
Genetic testing reads your DNA from a simple saliva sample and analyses it for variants linked to health, traits, and how your body functions. Phenome uses Whole Genome Sequencing, which reads your entire genetic code rather than just selected sections, giving a far more complete picture than basic DNA tests.
What are the different types of genetic tests?
Different genetic tests answer different questions. The main ones include:
- Comprehensive genomic testing: The all-in-one option, covering health risk, nutrition, medication, fitness, and more
→ Explore the Comprehensive Genomic Test
- Carrier screening: Looks at what you might pass to your children, for family planning
→ Explore the Carrier Screening Test
- Sports and performance testing: Focuses on fitness, strength, endurance, and recovery
→ Explore the Sports Performance Test
- Newborn testing: Maps a baby's genes early in life
→ Explore the Newborn Screening Test
If you want the full picture, comprehensive testing covers the most ground. If
Can your genes predict disease?
Not exactly. Your genes reveal tendencies and susceptibilities, not certainties. Carrying a variant linked to a condition usually means a higher or lower likelihood, not a guarantee, because lifestyle and environment also play a major role. This is why modern genetics increasingly focuses on prevention and health maintenance, not just risk.
How do your genes affect what you should eat? (nutrigenomics)
Your genes influence how your body processes nutrients, which is why diets work differently for different people. Genetic testing can reveal tendencies in how you handle carbohydrates, fats, caffeine, lactose, and certain vitamins, helping you tailor your nutrition to your body instead of following generic advice.
How do your genes affect medication? (pharmacogenomics)
Your genes influence how your body responds to certain medications, how well they work and how you tolerate them. Pharmacogenomic insights can help healthcare professionals choose safer, more effective options across common drug types, from pain relief to cardiovascular and mental-health medications.
Is genetic testing worth it?
Genetic testing is most worthwhile if you want to understand your body in depth and make more personalised health, nutrition, and lifestyle decisions. It's not a diagnosis and it won't predict your future with certainty, but it gives you a detailed, lifelong reference, your genes don't change, so you test once and revisit the insights as your life and science evolve.
How do you make sense of your results?
The best way to understand genetic results is with expert support, because the science is complex and some findings are sensitive. Phenome provides access to genetic counsellors who help you interpret what your results mean for you, so you get clarity and confidence rather than a confusing data dump.
→ Explore genetic counselling
→ Planning a Family: The Complete Guide
→ How Inherited Conditions Are Passed On
→ Are Athletes Born or Made? What the Science Says
→ How to Improve Your Athletic Performance: The Complete Guide
Questions
Is a DNA health test the same as an ancestry test?
No. Ancestry tests focus on heritage, while health genetic testing looks at how your genes affect your body, your metabolism, disease risk, medication response, and more.
Does genetic testing diagnose disease?
No. It reveals tendencies and susceptibilities, not diagnoses. Any concerning findings should be discussed with a healthcare professional.
Do your genes change over time?
No. Your DNA stays the same throughout life, so you only need to test once, though how your genes are expressed can shift with lifestyle (epigenetics).
What's the difference between Whole Genome Sequencing and a basic DNA test?
Whole Genome Sequencing reads your entire genetic code, while basic tests look at selected markers, so sequencing gives a far more complete and accurate picture.
Sources
- NHS (n.d.). Genetic and genomic testing. NHS website. https://www.nhs.uk/conditions/genetic-and-genomic-testing/
- MedlinePlus Genetics (n.d.). What are whole exome sequencing and whole genome sequencing? US National Library of Medicine. https://medlineplus.gov/genetics/understanding/testing/sequencing/
- MedlinePlus Genetics (n.d.). What are complex or multifactorial disorders? US National Library of Medicine. https://medlineplus.gov/genetics/understanding/mutationsanddisorders/complexdisorders/
- MedlinePlus Genetics (n.d.). What is pharmacogenomics? US National Library of Medicine. https://medlineplus.gov/genetics/understanding/genomicresearch/pharmacogenomics/
- Mullins V.A. et al. (2020). Genomics in Personalized Nutrition: Can You "Eat for Your Genes"? Nutrients, 12(10): 3118. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7599709/
- Centers for Disease Control and Prevention (2025). Epigenetics, Health, and Disease. CDC. https://www.cdc.gov/genomics-and-health/epigenetics/index.html
- Webborn N. et al. (2015). Direct-to-consumer genetic testing for predicting sports performance and talent identification: Consensus statement. British Journal of Sports Medicine, 49(23): 1486-1491. https://www.stir.ac.uk/research/hub/publication/582303
Longevity, in your inboxGet the latest from the Hub.
Evidence based guides on your gut, hormones, genes and healthspan, one thoughtful email a week.
Evidence based longevity, gut and DNA guides.