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Man on sofa, gripping stomach in pain due to unknown and uncontrolled diabetes and heart failure

How Diabetes Can Affect Your Heart Function

Reading time | 10 mins
Is it possible to live well with heart failure and type 2 diabetes? Rob Obey says yes, as long as you are aware of and manage both conditions.
Six weeks ago, and years after his initial diagnosis of heart failure, Rob began to show some alarming symptoms of diabetes. First, it was an unquenchable thirst and dry mouth. This was followed by stomach aches, a loss of sensation in his fingers and toes, and an unbearable sense of fatigue
Now feeling a lot better, Rob shares the warning signs – and how he manages both conditions the best he can.


Before I was diagnosed with type 2 diabetes, I knew very little about the condition. I knew that diabetics had to monitor their sugar intake, and some needed to inject insulin, but that was the extent of my knowledge. 

Then, six weeks ago, I got incredibly ill. For the life of me, I couldn't work out what was wrong. After trying to manage everything for a couple of days, I called my GP out of sheer desperation. He listened to what I had to say, then booked me in for some emergency blood tests. Within 48 hours, I had yet another diagnosis: type 2 diabetes and more medication to go along with it. 

I'm happy to say the medication is working. There have also been some positive effects which I didn't expect, and I'll come to those later. 

But, as you may know if you've read my other articles, I also live with and manage heart failure. That's what sparked today's article - heart failure and type 2 diabetes. Is there a link? How do I manage both? Did having one make it more likely I'd get the other? 

Related: Learning to Live with Heart Failure

It's a positive maze of questions, and, like the avid researcher I am, I spent hours trying to work out all the twists and turns to get to the answers. Let's start with a brief explanation of diabetes. 

Type 1 and type 2 diabetes: what's the difference? 

Diabetes is a condition that causes a person's blood sugar to become too high. This is linked to insulin production - a hormone made in the pancreas. Suppose your pancreas doesn't create enough insulin (or any insulin at all). In that case, you will have uncontrolled glucose levels in your blood. 

Unsurprisingly, type 1 and type 2 diabetes have plenty of stuff in common. Still, people have difficulty telling the difference between the two. 

Firstly, type 1 diabetes is much rarer than type 2. Both lead to serious health complications if not treated and managed, but type 1 only accounts for approximately 10% of diabetes in the UK. 

Type 1 diabetes often develops in childhood and adolescence, though it can occur in anyone under 40. The cause for type 1 is unknown, but some scientists think genetics may play a role. 

Essentially, type 1 diabetes happens when your pancreas can't make insulin. On the other hand, type 2 means that your body can produce insulin, but either not enough or not of a quality to work properly. 

As I mentioned before, the causes of type 1 are still largely unknown - but doctors know that lifestyle is not a contributing factor to the condition. On the other hand, there are several risk factors for type 2 diabetes, such as: 

  • Your weight - such as being overweight or obese 
  • Lack of exercise 
  • Where the most fat is stored in your body. If you carry a lot of weight in your stomach area, you may be more at risk of type 2 diabetes
  • Family history 
  • Race and ethnicity 
  • Age (especially 45+) 
  • Pregnancy 

Neither type 1 nor type 2 diabetes has a cure, but both can be managed. People with type 1 diabetes take insulin to control their blood sugar. Meanwhile, type 2 diabetes is chiefly managed with diet, exercise, and medication. Some people with type 2 can be prescribed insulin, but by no means all. 

The relationship between diabetes and heart conditions

Some time ago, I read that people with diabetes were at risk of developing heart disease.

I'm a little bit unusual in the sense that I had heart failure before I was diagnosed with type 2 diabetes. 

Most likely, my diabetes was caused by a poor diet, lack of exercise and being morbidly obese. Unlike type 1 diabetes, the symptoms of type 2 are more general and gradual. It's possible to live with type 2 diabetes for years without knowing - until you become ill, the same way I did. 

Related: Making it Through a Crisis, One Day at a Time

I'm not qualified to give you a complete medical explanation for the relationship between diabetes and heart conditions. Instead, I've taken this from the British Heart Foundation:

After we eat, we begin to digest foods and break carbohydrates down into glucose. In people who don't have diabetes, insulin is released by their pancreas when they eat. It acts as a signal for cells around their body to absorb the glucose and use it as fuel for energy.

If you have Type 2 diabetes, your body doesn't make enough insulin or can't use it, and the cells don't absorb enough glucose. This causes high levels of glucose in your bloodstream.

High glucose levels in your blood can damage the walls of your arteries and make them more likely to develop fatty deposits (atheroma).

If atheroma builds up in your coronary arteries (the arteries that supply oxygen-rich blood to your heart), this is coronary heart disease and can lead to a heart attack. If this happens in the arteries that carry blood to your brain, it can lead to a stroke. [1] 

As I said before, many people live with undiagnosed diabetes. If left unchecked, diabetes can lead to heart complications such as heart failure. Is it possible that my heart condition was caused by uncontrolled diabetes? 

Recognising the symptoms of type 2 diabetes when you have heart failure

The symptoms of type 2 diabetes are easy to miss and easy easier to explain away. Unfortunately, these symptoms tend to creep up on you, so burying your head in the sand won't change the situation. 

Here are some symptoms of type 2 diabetes to watch out for: 

  • An urge to go to the toilet a lot, especially at night 
  • Unquenchable thirst, no matter how much you drink 
  • Feeling exhausted, no matter how much sleep you get 
  • Losing weight without dieting 
  • Getting itchy "down there" or developing thrush 
  • Cuts and wounds taking longer to heal, or not healing at all 
  • Eyesight becoming blurred 
  • Increased hunger 

I started to suspect something when I caught myself drinking glass after glass of water and still wanting more. My mouth felt like sandpaper whenever I talked. Due to my heart failure, I'd been told not to drink more than 1.5 litres of fluid a day - but the thirst was driving me mad! At the peak, I was drinking more than 5 litres of water and still ached for more. 

My drinking water habits had a knock-on effect on my toilet schedule. I would wake up 2 or 3 times a night to use the bathroom. This getting up and wandering about began to affect my daily routine, too. I was tired throughout the day, even though I fought to keep the same sleeping pattern I'd always had. 

As a full-time caregiver, being tired all the time wasn't ideal. Some days, I needed to go back to bed and get the shut-eye I needed. When I managed to stay awake, I was rushing to the toilet every 20 minutes or so. This made leaving the house almost impossible, as I didn't want to get caught short. 

Related: Caregiving – When the Roles are Reversed

Two more symptoms were also getting harder and harder to handle. I was plagued by a constant stomach ache that wouldn't shift. Whenever I stood up too quickly or moved my head, I had a wave of light-headedness. 

The light-headedness didn't worry me too much, as I'd had it before as a side-effect of my heart failure medication. But the stomach ache was becoming too much to bear. 

All too quickly, another complication rose to the surface. Known as peripheral neuropathy, the best way to describe it is losing sensation in your extremities - especially your hands and feet. 

This wasn't painful, but it made day to day activities extremely dangerous. Pain may be a burden to bear, but it's the best warning sign for when to stop doing something. Using knives, holding hot drinks, and lifting pans are all risky when you can't feel them. Just because something doesn't hurt, it can do untold damage to your body. A knife slip can lead to a bad cut, which, with my healing issues, can quickly become infected.  

Having no sensation in your feet and toes can also affect your balance. I was often stubbing my toe on the furniture, or accidentally scraping myself on the walls. 

I had no idea how much I needed to look after my feet until I met with my podiatrist. She gave me a pedicure and a very graphic leaflet about the risk of amputation if I unwittingly hurt my foot. 

See, diabetes (both types) can lead to nerve damage and poor circulation. This means that minor cuts and scrapes on the feet can get infected and turn to ulcers, quickly getting out of control. 

Ulcers are open sores that can lead to a breakdown of skin and other tissues. If the ulcer is left untreated (or unnoticed), the tissue and skin around it can "die off" (gangrene), which may lead to amputation. 

Trust me, I'm now very, very careful when it comes to my feet!

What has this got to do with heart failure, I hear you ask?

First of all, some diabetes symptoms overlap with heart failure. The main one being tiredness or fatigue.

It’s no secret that heart failure affects how blood is pumped around your body. With circulation seriously affected, it can make diabetes symptoms much worse. If your extremities aren’t getting the blood they need, this can lead to peripheral neuropathy. As I’ve said above, peripheral neuropathy leads to numbness or loss of sensation, leading to unnoticed cuts and scrapes. Which, in turn, can cause abrasions or wounds to become infected and all the complications that arise with that.

Related: How Heart Failure Affects My Mental Health

The high blood sugar levels tied with diabetes can also cause damage to the vessels carrying blood to and from your heart. The sugar sticks to your red blood cells, causing build-up and blockages. With a severe enough blockage, the heart becomes starved of the oxygen it needs and essential nutrients.

In short, both feed directly into each other, making one big toxic relationship.

Managing diabetes when you have heart failure

Whether your condition is controlled by diet, medication or insulin, there are things you can do to help yourself. 

As mentioned, one of the first and most common symptoms of diabetes is thirst. As a heart failure patient, you most likely need to monitor your fluid intake. 

A great tip is to suck an iced lolly or ice cube. They quench the thirst without overloading you with fluid.

Of course, you should eat healthy food regardless, but especially with diabetes. No matter how much you crave sugar, you must make a concerted effort to reduce your intake.

As hard as it is when you have heart failure, exercise is beneficial in so many ways. The main two being increased circulation and weight loss.

It’s also essential to monitor several things as often as you can, such as:

If you smoke, now would be a good time to stop. Work with your healthcare team to learn the best ways to manage diabetes. The NHS also provides some wonderful, free services to help you quit smoking for good.

This leads me nicely onto some unexpected benefits of diabetes.

Glass half-full: some unexpected benefits of diabetes

Diabetes is a tough condition to manage – especially as it never goes away. It’s always at the forefront of my mind, and hours go into researching and monitoring both my conditions.

So, I don’t mean to sound flippant, and it’s not my intention to offend anyone. These are some benefits I found among the mess, and that’s not to say everyone will have them or feel the same way.

Related: The Fires of Hope – Life after a Heart Attack

But, before I received my type 2 diabetes diagnosis, I lost two stones without trying. Although I was panicking because of these new symptoms that seemingly came from nowhere, losing this weight helped my heart health. Carrying extra weight was putting strain on my heart, so the loss was a blessing in terrible circumstances.

Secondly, I no longer want or even like sweet food. I haven’t eaten chocolate since I was diagnosed, and I don’t miss it at all. I also used to love spicy food and ate it in unhealthy amounts. Again, my tastes have changed. I miss spicy foods more, undoubtedly, but I know that giving them more of a berth can only improve my health.

Finally, and this is massive, the medical monitoring I've received since being diagnosed has been second to none.

Because I'm classed as stable on my heart failure medication, I'm pretty much left alone.

Now, I'm constantly monitored. One mention of diabetes and I'm a priority.

Within a matter of weeks, I saw two nurses, a GP and a podiatrist. Then, they all made follow up appointments.

Let's hope this level of care continues.


If you have any common symptoms of diabetes, don’t delay get checked out. Some days (like hot ones), it’s natural to feel thirstier than usual. However, if you have a dry mouth and the thirst is unquenchable, it would be wise to check it out with your GP. Remember, the sooner you get checked, the quicker you and your health team can exercise some damage control.

Diabetes often imitates other conditions. Stay alert and don’t ignore symptoms even if you’re used to having them. With diabetes, you may notice other symptoms on top of what you managed before. Can a loss of sensation in your hands and feet be explained away by another condition? Or should you get yourself checked? I suggest the latter option.

If you are diagnosed, absolutely follow any advice you are given. Unbalanced blood sugar levels can play havoc with your body and potentially cause damage to your heart.

Pay very close attention to your feet. Any cut, swelling, infection, bruise should be checked by a doctor within 24 hours. There is too much risk to ignore even the most minor of injuries. It’s always better to be safe than sorry.

The good news is diabetes is treatable. For me, medication and lifestyle changes brought the condition under control quite quickly. It’s difficult to tackle diabetes and heart failure together. Still, I’d rather put in the effort than face any nastier – and fatal – consequences.


[1] British Heart Foundation,, last accessed September 2021

NPS-IE-NP-00341 November 2021