Skip to content

42 factors that affect blood sugar

It can sometimes feel like there are a million factors that affect blood sugar – but here’s a list of 42 factors that affect blood sugar, courtesy of diaTribe.

42 factors that affect blood sugar - like a puzzle

Not sure how these factors affect your blood glucose? Download the PDF below with more details, or check out the original article. Do you have any other factors to add, in your experience? Diabetes can be so confusing, sometimes! Like a puzzle with so many different options for how to make sense of it.


  1. Carbohydrate quantity
  2. Carbohydrate type
  3. Fat
  4. Protein
  5. Caffeine
  6. Alcohol
  7. Meal timing 
  8. Dehydration
  9. Personal microbiome


  1. Medication dose
  2. Medication timing
  3. Medication interactions
  4. Steroid administration
  5. Niacin (Vitamin B3)


  1. Light exercise
  2. High intensity and moderate exercise
  3. Level of fitness/training
  4. Time of day
  5. Food and insulin timing


  1. Too little sleep
  2. Stress and illness
  3. Recent hypoglycemia
  4. During-sleep blood sugars
  5. Dawn phenomenon
  6. Infusion set issues
  7. Scar tissue/lipodystrophy
  8. Intramuscular insulin delivery
  9. Allergies
  10. A higher BG level (glucotoxicity)
  11. Periods (menstruation)
  12. Puberty
  13. Celiac disease
  14. Smoking 


  1. Expired insulin
  2. Inaccurate BG reading
  3. Outside temperature
  4. Sunburn
  5. Altitude

Behaviour and Decisions

  1. More frequent BG checks
  2. Default options and choices
  3. Decision making biases
  4. Family and social pressures

Find out more about the explanations behind these 42 factors on the original diaTribe article here or download a helpful summary below that explains how each of these factors affects blood glucose.

What to read next?

Is sugar addiction at the heart of Type 2 diabetes?: South African family physician, Dr Beth Vale, works in the public health system and reflects on Type 2 diabetes in this article.

The Type 1 diabetes toolkit: what you need to carry at all times

Time in target: what it is, why it’s important, and how it can help

Photo by Kieran Wood on Unsplash

What to read next
Join South Africans with Diabetes on Facebook

Join our diabetes community


  1. […] are two ways that emotions affect blood glucose: an indirect pathway, and a direct pathway. The indirect pathway is lifestyle related. If you’re […]

  2. […] If you’re on insulin, you can work out your insulin to carb ratio. For example, when I eat 1 carb, I need to inject 3 units of insulin. Although there are many factors that affect blood sugar – the temperature, hormones, sickness, sleep – being able to accurately test the effect of different food can help significantly. Here are the 42 factors that affect blood sugar. […]

What do you think?

Sweet Life is a registered NPO/PBO (220-984) with a single goal: to improve diabetes in South Africa. We are funded by sponsorships and donations from aligned companies and organisations who believe in our work. We only share information that we believe benefits our community. While some of this information is linked to specific brands, it is not an official endorsement of that brand. We believe in empowering people with diabetes to make the best decisions they can, to live a healthy, happy life with diabetes.