Gluten Free Glee

Complications

What can happen if coeliac disease is left untreated

Nicola Walpole
Nicola WalpoleSpecialist Coeliac Dietitian
Philippa Lee
Philippa LeeFounder, Gluten Free Glee

Fast Facts:

If gluten isn't avoided, coeliac disease can lead to serious complications, including:

🩸 Malabsorption - Poor nutrient absorption

🦴 Osteoporosis - Weakened bones and fracture risk

🥱 Malnutrition - Severe nutrient loss

🥛 Lactose intolerance - Temporary dairy sensitivity

🦠 Cancer risk - Slightly increased risk of gut cancers

🫄 Pregnancy - Higher risk of miscarriage or low birth weight

Following a strict gluten free diet helps prevent these complications.

❓ What Are the Complications of Coeliac Disease?

Complications of coeliac disease typically only affect people who continue to eat gluten after diagnosis, or those who remain undiagnosed, which can be a common problem in milder cases. That's why it's so important to stick to a gluten free diet once diagnosed.

👉🏽 Click here to read about how coeliac disease is diagnosed.


🩸 Malabsorption

Malabsorption occurs when your small intestine cannot absorb essential nutrients properly. Common deficiencies include:

  • Iron - Can lead to iron-deficiency anaemia, causing fatigue and weakness
  • Vitamin B12 & Folate - Low levels can cause megaloblastic anaemia, leading to dizziness, tiredness, and shortness of breath
  • Calcium & Vitamin D - Increases the risk of osteoporosis

🦴 Osteoporosis

Osteoporosis (weakened bones) leads to around 300,000 fractures each year in the UK, and 9 million globally. Studies show that up to 75% of people with coeliac disease have low bone mineral density at diagnosis - but this often improves significantly after 1 year on a gluten free diet.

Risk factors include:

  • Late or missed diagnosis
  • Not sticking to a gluten free diet
  • Ongoing gut damage (villous atrophy)
  • Low body weight and lactose intolerance
  • Ageing, menopause, smoking, inactivity
  • Certain medications (e.g. steroids)

If you are concerned, speak to your GP or Consultant - they may refer you for a DEXA scan to check your bone health.


🥱 Malnutrition

In severe cases, coeliac disease can lead to malnutrition, where your body lacks the nutrients it needs to function or recover properly.

Symptoms include:

  • Fatigue, confusion, and dizziness
  • Muscle weakness and unintended weight loss
  • In children: delayed development and stunted growth

Treatment may involve high-calorie diets and nutritional supplements under medical supervision.


🧠 Neurological Problems

Up to 60% of people with coeliac disease have neurological symptoms at diagnosis - yet these are often overlooked or misdiagnosed. Those with non-gut symptoms are typically diagnosed almost 10 years later on average.

Common neurological complications include:

  • Peripheral neuropathy - Tingling, pain, numbness in hands and feet
  • Ataxia - Poor coordination, clumsiness, slurred speech
  • Cognitive issues - Brain fog, memory lapses, poor focus
  • Mental health symptoms - Anxiety, depression, and mood swings

It's important to note that potential mental health impacts, such as anxiety and depression, can arise from both the condition itself and the stress of managing to a strict gluten free diet.


🥛 Lactose Intolerance

Untreated coeliac disease can lead to temporarily lactose intolerance. This happens when gut damage reduces the enzyme needed to digest lactose (the natural sugar in dairy).

Symptoms include: bloating, diarrhoea, and stomach discomfort after consuming milk or dairy.

The good news? Lactose intolerance often improves once your gut heals. Until then:

  • Use lactose-free dairy alternatives
  • Consider calcium supplements to meet your daily needs

🦠 Increased Cancer Risk

Cancer is a very rare but serious complication of untreated coeliac disease. Someone with untreated coeliac disease has a slightly increased risk of developing certain rare gut cancers, including: 

  • Small bowel cancer
  • Small bowel lymphoma
  • Hodgkin lymphoma

However, recent research shows the risk is lower than previously thought and returns to normal (same as that of the general population) once a gluten free diet is followed.


🫄 Pregnancy and Coeliac Disease

If coeliac disease is undiagnosed or not well-managed during pregnancy, it may increase the risk of:

  • Recurrent miscarriages
  • Low birth weight
  • Premature birth

Following a gluten free diet and getting the right nutrients is essential for both maternal health and baby's development.


🎯 Quick Recap:

Untreated coeliac disease can cause serious complications - from bone loss and malnutrition to fertility issues, cancer, and nerve problems. Most of these complications are preventable by sticking to a strict gluten free diet, staying informed, and keeping up with regular check-ins with your GP or specialist.

👉🏽 Read more about getting an annual coeliac review here.