POTS, Reactive Hypoglycemia and Blood Sugar: What’s the Connection?

When most people think about Postural Orthostatic Tachycardia Syndrome (POTS), they think about heart rate, dizziness and blood pressure changes. But the autonomic nervous system — the system affected in POTS — is involved in far more than cardiovascular regulation alone.

It also plays an important role in blood sugar control.

For some people living with POTS, symptoms that occur after eating may not solely be part of a “POTS flare.” Instead, they may be linked to reactive hypoglycemia: a drop in blood glucose levels occurring in the hours after a meal.

Why does this happen?

The autonomic nervous system helps regulate digestion, insulin release and glucose balance after eating. In people with autonomic dysfunction, these systems may not respond as efficiently as they should.

After consuming a meal — particularly one high in refined carbohydrates — blood sugar levels rise. In response, the body releases insulin to move glucose from the bloodstream into cells. In reactive hypoglycemia, this insulin response can become dysregulated, leading to a sharper drop in blood sugar afterwards.

This “spike-and-crash” pattern may contribute to symptoms such as:

• Shakiness

• Palpitations

• Dizziness

• Sweating

• Fatigue

• Brain fog

• Weakness

• Suddenly feeling unwell after meals

The challenge is that these symptoms can look almost identical to a typical POTS flare, making reactive hypoglycemia difficult to recognise.

Why does it matter?

Beyond the immediate symptoms, repeated blood sugar spikes and crashes may place ongoing stress on the body’s glucose regulation system over time.

If left unmanaged, this pattern may contribute to worsening insulin sensitivity and increase the risk of developing insulin resistance and type 2 diabetes later on.

This is one reason it is important to look at POTS through a broader whole-body lens, rather than focusing on heart rate and blood pressure alone.

Supporting blood sugar regulation in POTS

The encouraging part is that there are practical strategies that can help improve blood sugar stability and reduce symptom severity.

Nutrition strategies

From a dietary perspective, many people benefit from:

• Smaller, more frequent meals

• Pairing carbohydrates with protein, fat and fibre

• Reducing large loads of refined carbohydrates

• Avoiding long gaps between meals

• Prioritising balanced meals that support steadier glucose release

These approaches may help reduce rapid blood sugar fluctuations and improve energy levels throughout the day. Working with a POTS-aware dietician can be very beneficial.

The role of exercise

Exercise is one of the most powerful tools available for improving blood sugar regulation.

During exercise, muscles are able to take up glucose directly from the bloodstream, independent of insulin. Over time, regular exercise improves insulin sensitivity, meaning the body becomes more efficient at managing glucose levels.

Strength training is particularly valuable because increasing lean muscle mass improves the body’s overall capacity to store and utilise glucose effectively.

This is one reason exercise programs for POTS often include both aerobic conditioning and progressive resistance training. It is not only about cardiovascular adaptation — it is also about improving the function of the broader metabolic system.

Looking at the bigger picture

POTS is a complex condition that often affects multiple systems within the body. For some people, blood sugar instability may be another important piece of the puzzle contributing to symptoms and day-to-day crashes.

Understanding these overlaps can help guide more targeted management strategies and support better long-term health outcomes.

At CardioCare, we take a whole-person approach to POTS management, recognising the important connections between autonomic function, cardiovascular health and metabolic health.