Ajax Harwood Clinic

Multiple sclerosis

In multiple sclerosis the immune system attacks the insulating sheath around nerves in the brain and spinal cord, which slows or blocks the signals travelling along them. Where that happens decides the symptom — vision, sensation, balance, strength or bladder — which is why MS looks so different from one person to the next.

Get help straight away if

These are uncommon, but they need same-day care — go to an emergency department, do not wait for an appointment.

Contact us promptly if

Not an emergency, but worth being seen sooner rather than waiting it out.

What usually happens

The outlook is not what it was. The treatments available now change the course of the condition for most people, and the picture many arrive with — inevitable, rapid, ending in a wheelchair — reflects how MS behaved before those existed rather than how it behaves now.

There is an important difference between a relapse and a flare of old symptoms. Heat, infection, exhaustion and stress can all bring back symptoms you have had before, sometimes vividly, without any new inflammation. That settles as the trigger settles, and is treated by treating the trigger.

A genuine relapse means something new, or something clearly worse, lasting more than about a day. That is the one worth contacting us about promptly rather than waiting.

Fatigue in MS is not ordinary tiredness and it is one of the most disabling parts for many people, while being invisible to everyone else. It is worth raising specifically, because there are things that help.

The unglamorous things carry more weight than they sound: vitamin D, not smoking, staying active, and treating infections promptly all affect how MS behaves over years.

At your appointment

Care shared with neurology, with a good deal handled here between appointments — infections, bladder symptoms, mood, spasticity and the practical business of living with it.

We will ask carefully whether a new symptom is genuinely new or an old one resurfacing, because that distinction decides what happens next.

Attention to bladder symptoms and to fatigue, both of which are common, treatable, and routinely under-reported because people assume they are simply part of it.

Vitamin D, vaccinations and, where you are on treatment that affects the immune system, the extra monitoring that comes with it.

Should I be tested?

Last reviewed 2026-09-23

A common question after tingling or numbness is whether it could be MS.

"Do I have MS?" after tingling or numbness

Tingling or numbness is common, and searching it online often points to MS. Most of the time, it isn't MS. Multiple sclerosis usually causes symptoms lasting more than a day, not seconds or minutes. Certain features raise more concern. These include sudden vision loss with eye pain, double vision, or numbness spreading over hours. A strange shock feeling down your back when you bend your neck forward is another one. New bladder trouble alongside numbness also matters. Brief tingling that comes and goes, or numbness in one small area like your hand, is usually something else. MS is diagnosed with an MRI and a specialist. There isn't a blood test that confirms or rules it out.

Tests you may hear about

Worth asking

Curious what your doctor is weighing up? The clinical tool we use for multiple sclerosis is open to anyone — it is detailed and written for clinicians, and you are welcome to read it.

Open the clinician reference →

General health information for Ajax Harwood Clinic patients and the public — not medical advice, and not a substitute for seeing your own doctor. In an emergency call 911.