Sensory Changes

Sensory changes

Several chest, heart and stroke conditions can have effects on your vision, hearing, sense of smell and taste, or how you experience sensations. This kind of change can also cause pain.

Stroke can affect any or all senses. Your brain processes what you see, hear, touch, taste, and smell – if the parts of the brain which handle one or more of these processes is damaged by your stroke, it can affect your senses. After stroke, many people experience visual disturbances, and you may lose some or all hearing in one ear.

Chest and heart conditions may affect your senses, especially your vision, which is often blurred or unfocused when you are experiencing heart problems or when you are breathless. Some conditions that affect your breathing may also affect your sense of smell and/or taste.

Long Covid is often associated with a loss of your sense of smell and/or taste. The impact on balance and breathing, as well as fatigue, can also affect your eyesight and make it harder to see clearly.

Vision

Disturbances to how you see are a common side-effect of many conditions, both serious and minor. Breathlessness or low blood pressure, heart problems, stroke or injury can all cause changes to your vision. Vision also changes with age and with general health.

Common changes in vision that people experience include:

• Blurring or a loss of focus, especially in bright light or when changing focus.
• “Floaters” – small, squiggly shadows that hang in your vision. These are normal in small numbers, but may be a sign of damage if you are frequently distracted by them or if they block what you are looking at.
• Difficulty adapting to changes in light levels.
• Double vision.
• Uncontrollable eye movements.
• Dry eyes.

After stroke, partial or complete blindness is a possible side effect. Because this blindness is usually caused by issues with the nerves, not with the eye itself, glasses may not help – on the other hand, people with this kind of blindness can sometimes recover fully from it.

Hearing

Hearing may be affected by a stroke, or by blockages or inflammation in the ears. This can also affect your balance.

Common hearing problems include:

• Loss of hearing on one or both sides
• Tinnitus – a persistent noise which doesn’t come from anywhere. This may be present all the time, or it may come and go.
• Inability to hear noises of a certain pitch. As we age, it is normal for the range of noises we can hear to shrink – it becomes more difficult to hear very high or very low sounds – but some conditions can make this happen much faster.
• Things sounding muffled or unclear

If you are experiencing hearing problems, you should speak to your health professional, and may be referred to an audiologist (hearing specialist) who will be able to give you a free hearing check.

Aids are available to help with hearing loss, including in-ear hearing aids and closed-caption programmes. It may also help to look at people when they are talking, to pick up lip movements and facial expressions, which can help you to interpret unclear sounds.

Smell and taste

Smell and taste are closely linked, so it is very common for both to be affected if one of them is. A loss of smell, taste, or both is called anosmia (an-OZ-me-ah). Partial or complete anosmia is a common side effect of many conditions. It may be temporary, and come back with time; on the other hand, it may be permanent.

Because smell and taste are both based on detecting certain chemicals, it is quite common for people with anosmia to lose only some of their sense of smell or taste. For example, you may struggle to taste sweet things, but be able to taste salty ones.

Anosmia can often be caused by congestion of your nose and throat – this is one of the reasons people with breathing problems are more likely than average to experience anosmia. If this is the case, then decongestants or chest clearing exercises may help to restore your sense of smell and taste.

You can also treat anosmia in some cases using scent training, a process which builds a habit of smelling the same thing regularly to remind your brain how to process it.

Following a stroke, some people also report that, although they can still smell and taste things, their experience of them has changed. For example, you may find that you no longer like something that used to be your favourite smell, or that something that used to taste horrible now tastes good to you. This can take some getting used to. Because it is so different for different people, you may have to experiment for a while to find out how your tastes have changed.

It is also possible, especially after a stroke, to develop something called hyperosmia, where your sense of smell is much more sensitive.

Stroke may also cause phantosmia (fan-toz-me-ah) which is where you smell things that are not there. Many people who have a stroke find that they smell something which is described as smoke or burning toast, while others may experience a metallic, coppery taste. Contrary to popular belief, this does not only happen when a stroke is actually occurring – some people may continue to smell or taste these “phantoms” during their recovery.

Touch

Stroke and Long Covid both affect the nervous system, which means that they can have significant effects on how you experience touch. You may feel numbness, tingling, or itching where you would expect a different sensation. On the other hand, you may find that you become hypersensitive at times – the feeling of touching something may be much stronger, and even painful.

This is closely related to chronic pain, but does not always mean you will experience pain.

Synaesthesia

Following stroke or other brain or nerve damage, some people may develop something called synaesthesia. This is a condition where the pathways in your brain become confused, and may “cross over” between senses – for example, you may experience sounds as having a colour, or shapes as having a taste.

Synaesthesia is harmless, but it can take some getting used to. If you have developed synaesthesia, you may find that what you like and dislike changes; you may also find it difficult to describe your experience to other people. Usually, people with synaesthesia get used to it quite quickly.

Spatial neglect

Following a stroke, some people experience something called spatial neglect. This means that some or all of the senses on the affected half of your body do not function fully, so you may forget that things in that half of your world exist. This most commonly occurs on the left, because most strokes affect the right half of the brain.

For example, people with spatial neglect may fail to shave the left side of their face, ignore food on the left side of their plate, or be unable to see or hear people approaching from that side. It is common to be unaware that you have this condition, and to think nothing is wrong.

Spatial neglect can be treated over time by bringing your attention repeatedly towards things in the neglected area. If you have spatial neglect, you will probably be supported in this treatment by members of your stroke team, particularly neurologists, occupational therapists, and stroke nurses.