Hi, LLSR. Welcome to the forum!

1. Yes, your symptoms sound like MG, in that it sounds as though you have fatigable muscle weakness (the hallmark of MG).

2. Yes, it's very typical of MG to vary that way! It's a highly unpredictable disease, but most people start to notice what their particular pattern is. MG can still surprise even those that have had it for years.

3. Are you sure you don't have ocular weakness/ptosis (toe-sis)? Have you taken photos of your eyelids when you're doing better and then when you're worse? MGers present in all types of ways, but the classic one is for it to progress from the head muscles and then downward. A neuro-ophthalmologist can tell you for sure if your eyelid muscles are fatiguing.

4. Yes, the approach is reasonable. Why? Because if they can rule in or out other diseases, and your AChR test or others are positive, then you don't necessarily have to put yourself through yet another test when the clinical suspicion for MG is high.

5. Yup.

Have you had the blood clotting tests done, such as lupus anticoagulant, antiphospholipid antibody, etc.?

Have you ever had your vitamin B12 tested? It's as common as a D deficiency. I hope you are supplementing with D and will continue to do so. If you have lupus, you should know that recent studies have shown not only a direct correlation between a D deficiency and lupus, but they are now finding that having a deficiency might contribute to getting lupus and other AIs!

It actually sounds as though your chest wall muscles ARE affected. If an activity leaves you breathless, then that probably indicates a fatigable weakness of those muscles.

Lupus is hard enough to live with! I hope you have a regular rheumatologist who will periodically check things such as your kidney function. You need to be very aware of that, because some drugs you might be offered (for lupus or MG) could adversely affect the kidneys.

MG has a high learning curve. If you end up with that diagnosis, make sure you come back and read as much as you can or ask lots of questions! The other disease that your doctor tested for is LEMS (Lambert-Eaton Myasthenic Syndrome). That "cousin" of MG can come with a risk for small cell lung cancer, so it's good to know which one you have!

Many things can make MG worse, such as lack of sleep, stress, infection, and even drugs such as Plaquenil (some people are fine with it). Extremes of heat and cold can make MG much worse, so be careful out there! If you do get overheated, make sure you cool down right away. Sit in front of a fan or a freezer! Run your wrists under cold water. Anything to cool down, especially the core muscles.

Start keeping a diary of your symptoms. Write down how you're doing before AND after an activity. It will really help. And the more a person does with MG, the worse they can get. Running errands for one hour might be ok, but doing it for three might make your body force you into a nap. Naps are very beneficial for MG and needing one is often the first sign of the disease!

Anything else we can help with? Just take it easy until you get a diagnosis. And if you get worse, such as not being able to swallow, move, or breathe well, then dial 911. We can get a "MG crisis," where muscles can stop working. Don't be scared about that, just be aware and prepared!

Annie