Black Outs?

insane said:

Hey guys. I just started cycling long distances like 10-13km, and sometimes i get this throbbing headache while cycling. When i get off the bike, and sit down, immediately my vision blacks out, like blood rushing to my eyes or something. Any reason why, and is it linked to the fact that I have a high metabolic rate?

Extra info: I'm 19, 174cm tall, but due to my high metabolic rate, i weigh a frightening 40kg.

l would go see a doctor before you do any more strenious activity and btw you are seriously under weight even for a healthy cyclist.

You need to see a doctor before you continue cycling. Losing consciousness or nearly doing so needs to be take very seriously. In no way can anyone online diagnose or even credibly guess what the underlying issue might be.

alienator said:

You need to see a doctor before you continue cycling. Losing consciousness or nearly doing so needs to be take very seriously. In no way can anyone online diagnose or even credibly guess what the underlying issue might be.

Thanks guys, will go and check with my family doctor, its obviously an on and off thing, that can get pretty freaky at times.

insane said:

Hey guys. I just started cycling long distances like 10-13km, and sometimes i get this throbbing headache while cycling. When i get off the bike, and sit down, immediately my vision blacks out, like blood rushing to my eyes or something. Any reason why, and is it linked to the fact that I have a high metabolic rate?

Extra info: I'm 19, 174cm tall, but due to my high metabolic rate, i weigh a frightening 40kg.

Part-if-not-all of the problem is due to some level of hypotension which is probably exacerbated by some level of dehydration ...

Drink at least 100ml (?) of fluid every 20 minutes.

alfeng said:

Part-if-not-all of the problem is due to some level of hypotension which is probably exacerbated by some level of dehydration ...

Drink at least 100ml (?) of fluid every 20 minutes.

Wow. I guess there's no need to see a doctor then.....of course, you're could be absolutely wrong. Al, what if it is transient hypotension that's causing the issue, but instead of volume related problem, the hypotension is caused by a vagal response? Hmmm. That doesn't fit your theory. What if it's related to a medication issue? Hmmm. That doesn't fit your theory. What if it's a disease process (Both hypo- and hyper-glycemia can cause similar symptoms.). What if it's a respiratory problem? The same thing can happen. What if it's a brain issue? Hmmm. Maybe we should just rely on doctor's to provide medical diagnoses so that we can free up bike mechanics to do what they're qualified to do: work on bikes.

alienator said:

Wow. I guess there's no need to see a doctor then.....of course, you're could be absolutely wrong. Al, what if it is transient hypotension that's causing the issue, but instead of volume related problem, the hypotension is caused by a vagal response? Hmmm. That doesn't fit your theory. What if it's related to a medication issue? Hmmm. That doesn't fit your theory. What if it's a disease process (Both hypo- and hyper-glycemia can cause similar symptoms.). What if it's a respiratory problem? The same thing can happen. What if it's a brain issue? Hmmm. Maybe we should just rely on doctor's to provide medical diagnoses so that we can free up bike mechanics to do what they're qualified to do: work on bikes.

First, I did NOT say that insane shouldn't see a doctor ... apparently, literacy is a gift which you did not receive -- reread what I wrote AND reread your knee-JERK reply ...

And, rest assured, I am NEITHER the second coming of Edgar Cayce NOR am I a mind reader ...

I was positing a plausible cause based on the DESCRIBED SYMPTOMS which I believe the OP could/should investigate ...

If the OP had provided OTHER SYMPTOMS, then I might not have made the suggestion that I made.

Regardless, your declaration that diagnoses cannot be made remotely is simply uninformed (or, a prevarication on your part ... something which you seem to do at times) -- doctors do it all the time when they say "take two aspirin and call me in the morning" (to cite just one example).

What if, indeed ...

At least (?), you seem to be admitting that the problem may be hypotension ...

Regardless, I wasn't making a diagnosis ...

OR, perhaps you can explain how "part-if-not-all" qualifies as a diagnosis?

BTW. 'I' doubt that if the problem is indeed hypotension that it could be related to the vagus nervous system because if that were the case then would the OP would have a headache prior to each episode?

Does any other activity/whatever cause the OP to have a headache + have his/her vision momentarily black out?

Does the OP ever have postural hypotension?

We don't know. S/He didn't say.

I'm not going to preclude the benefit that the OP may-or-may-not have by going to a chiropractor ...

But, you tell me if YOU really think THAT a "vagal response" is truly a possibility after you really think about the DESCRIBED SYMPTOMS vs. those which you are imagining which were not described.

I think not.

Don't you think that if the OP's symptoms were truly the consequence of a "vagal response" that s/he would black out sooner while riding?!?

The OP did not indicate that s/he was taking medications, yet ... while the OP may be taking medications, the presumption one must make is that s/he is not ... because, if such were the case then s/he should know the possible adverse affects which said medications may impart.
[INDENT]When you have a conscious accident victim, don't you ask them if they are taking any medications?
[/INDENT]Blood sugar? Again, don't you think the symptoms (i.e., headache followed by vision black out) might have manifested themselves at least one other time during the preceding day/weeks/months/years while doing other things AND the OP would have mentioned it?

The OP did not indicate a problem breathing. Now, while "10-13km" may not be a long distance for either of us to ride, some people clearly think that it is.

If you look at the OP's bike, it does NOT have water bottle cages on it ...

Presuming YOU (i.e., alienator) live closer than "10-13km" to campus, would YOU wear a hydration pack for a ride which was just to campus, or back?

I suspect that the OP does not use a hydration pack ... maybe, s/he should.

Unfortunately, the litigious nature of OUR culture all but demands what many would deem to be unnecessary tests ... it has become part of the mindset.

Of course, most doctors ARE allopathically oriented ... it has been the way of Western medicine for decades ... part of the "better living through chemistry" philosophy. Another part of the mindset.

Don't you think that the FIRST thing that the OP needs to eliminate as a possible cause is the obvious?
[INDENT]If your car/motorcycle stops running and the 'needle'/(display) on the fuel gauge indicates the tank is empty do you have it towed to the mechanic, first, or do you put gasoline in the tank?
[/INDENT]It could be a problem with the brain, but wouldn't even-YOU anticipate that the problem would also manifest itself in less physically stressful situations & have been so ennumerated by the OP?

There MAY indeed be an underlying problem that DOES need further testing to properly diagnose. BUT, there may not be.

Wouldn't a good doctor would have the OP eliminate the obvious, too, BEFORE proceeding with more extensive & comprehensive testing.

Does 1 + 1 still equal 2?

OR, did you want to make it more complex than it is?

Sometimes, a sprained ankle is just a sprained ankle and not a broken ankle or torn ligaments ...

Sometimes, a sore throat is just a sore throat ...

Sometimes, a problem may just be a matter of dehydration.

Wow, indeed!

alfeng said:

First, I did NOT say that insane shouldn't see a doctor ... apparently, literacy is a gift which you did not receive -- reread what I wrote AND reread your knee-JERK reply ...

No, instead you proposed something and explicitly did not suggest the OP see a doctor. That is reckless full stop. Your statement was that of an ignoramus. FWIW, I'll gladly be a jerk when idiots offer medical "advise" as you did without having seen the OP, gotten a hx, and etc.

Quoted post said:

I was positing a plausible cause based on the DESCRIBED SYMPTOMS which I believe the OP could/should investigate ...

A plausible cause based on a very small set of symptoms and zero medical hx or exam, all things that a real live doctor, physicians assistant, nurse practitioner, or paramedic would do

Quoted post said:

If the OP had provided OTHER SYMPTOMS, then I might not have made the suggestion that I made.

A smart person would have said, "see a doctor" and kept his mouth shut re: a "tx plan."

Quoted post said:

Regardless, your declaration that diagnoses cannot be made remotely is simply uninformed (or, a prevarication on your part ... something which you seem to do at times) -- doctors do it all the time when they say "take two aspirin and call me in the morning" (to cite just one example).

Doctors don't diagnose over the phone. They may come up with a working diagnosis, but they absolutely will not make a diagnosis without examining the patient and/or having a complete medical hx. Show me a medical school that will instruct is soon-to-be doctors that it's ok to make a diagnosis based on the information the OP gave. It is, okay, however, to come up with a first step in a tx plan, a step which could also further refine a working diagnosis and formulate a definitive tx plan.

Quoted post said:

At least (?), you seem to be admitting that the problem may be hypotension ...

That's right. I did. Anyone who doesn't first and foremost consider the range of possible causes for the given signs and symptoms is a [censored]. Note that hypotension resulting from hypovolemia is far from the only consideration. In fact, it's not necessarily the first consideration.

Quoted post said:

BTW. 'I' doubt that if the problem is indeed hypotension that it could be related to the vagus nervous system because if that were the case then would the OP would have a headache prior to each episode?

Well, the headache idea is 100% wrong. It's not necessary at all to have a headache preceding a syncopal or near syncopal episode 2° to vagal stimulation. Personally, I've treated more than a few patients, seen more than a few patients who've experienced syncope 2° vagal stimulation w/out a headache. A lot of the time it was with someone taking a dump on the toilet, bearing down hard to defecate, and next finding themselves waking up on the floor.

Quoted post said:

Does any other activity/whatever cause the OP to have a headache + have his/her vision momentarily black out?

Does the OP ever have postural hypotension?

Those are the questions a medical professional would have asked if evaluating a patient. A medical professional wouldn't have, in an internet forum, said, "Drink water" and left it at that. They would have referred the OP to a doctor and likely stated that there are a host of things that could have caused a near syncopal episode and that the OP needed a proper evaluation.

Quoted post said:

But, you tell me if YOU really think THAT a "vagal response" is truly a possibility after you really think about the DESCRIBED SYMPTOMS vs. those which you are imagining which were not described.

Yes it is a possiblity as stated above.

Quoted post said:

I think not.

That's obvious from the ignorance you display.

Quoted post said:

Don't you think that if the OP's symptoms were truly the consequence of a "vagal response" that s/he would black out sooner while riding?!?

Not necessarily. There easily could be an underlying condition at the root of the vagal response.

Quoted post said:

The OP did not indicate that s/he was taking medications, yet ... while the OP may be taking medications, the presumption one must make is that s/he is not ... because, if such were the case then s/he should know the possible adverse affects which said medications may impart.

This is absolutely, hilariously wrong. Patients should know about the side effects of their medications? Well, dunce, where'd you come up with that? Frankly, some doctor's don't know all of the possible side effects, especially side effects from taking multiple medications. That's why pharmacists often won't fill a script but instead will call the doctor and tell them there's a problem with their script as written. Moreover, there are a huge number of people who don't even know the names of their meds, let alone the side effects. "I take a red pill in the morning, with 2 of the long white ones."

Quoted post said:

When you have a conscious accident victim, don't you ask them if they are taking any medications?

When I treated patients, I did so. What I didn't do was suggest a course of treatment in internet forums based on my experience as a bike mechanic.

Quoted post said:

Blood sugar? Again, don't you think the symptoms (i.e., headache followed by vision black out) might have manifested themselves at least one other time during the preceding day/weeks/months/years while doing other things AND the OP would have mentioned it?

That statement is the perfect display of your presumptuous idiocy and the shallow nature of your knowledge. As a person who was a Type I diabetic for 27 years, I can tell you that, from personal experience, you are flat out wrong. Full stop. (Yes, you can be cured of IDDM with a transplanted pancreas.). As a medic, who took treating diabetics very personally, I can without hesitation say that, again, you have no clue what you are talking about, based on my experience treating diabetics.

Quoted post said:

If you look at the OP's bike, it does NOT have water bottle cages on it ...

So are we then to take that as fact that the OP didn't have water on rides and dehydrated? Hmmm?

Quoted post said:

Presuming YOU (i.e., alienator) live closer than "10-13km" to campus, would YOU wear a hydration pack for a ride which was just to campus, or back?

I wouldn't, but I see students arriving on campus with hydration packs on. Quite a few students.

Quoted post said:

Unfortunately, the litigious nature of OUR culture all but demands what many would deem to be unnecessary tests ... it has become part of the mindset.

Don't even try that excuse. I am talking about what responsible people and medical professionals would do. Unnecessary tests have nothing to do with this

Quoted post said:

Of course, most doctors ARE allopathically oriented ... it has been the way of Western medicine for decades ... part of the "better living through chemistry" philosophy. Another part of the mindset.

Ah, another excursion in a tangent direction that bears no significance toward the topic at hand, which is the idiocy and ignorance you displayed.

Quoted post said:

Don't you think that the FIRST thing that the OP needs to eliminate as a possible cause is the obvious?

The responsible thing for the OP to do is schedule an appointment with his doctor. Syncope and near syncopal episodes need to be evaluated by a physician. Full stop.

Quoted post said:

There MAY indeed be an underlying problem that DOES need further testing to properly diagnose. BUT, there may not be.

A responsible medical professional works to rule out complicating factors and other possible diagnoses. Example: people with cough, shortness of breath, and fever being discharged with a dx of "rule out pneumonia." The difference is subtle and massively important.

Quoted post said:

Wouldn't a good doctor would have the OP eliminate the obvious, too, BEFORE proceeding with more extensive & comprehensive testing.

A doctor would want to see the patient.

Quoted post said:

Does 1 + 1 still equal 2?

Sorry, that pat response does not apply at all and is an empty statement designed to divert someone's attention from your weak arguments.

Quoted post said:

OR, did you want to make it more complex than it is?

First, I don't know how complex it is because I'm not a doctor, and I didn't make it complex at all. "See a doctor": easy peasy.

Sometimes, a sprained ankle is just a sprained ankle and not a broken ankle or torn ligaments ...

Quoted post said:

Sometimes, a sore throat is just a sore throat ...

Sometimes, a problem may just be a matter of dehydration.

More throwaway statements.

The correct answer for the OP is: don't look for medical advise on an internet forum. You don't know where that advice is coming from. Leave your questions for a doctor.

alienator said:

No, instead you proposed something and explicitly did not suggest the OP see a doctor. That is reckless full stop. Your statement was that of an ignoramus. FWIW, I'll gladly be a jerk when idiots offer medical "advise" as you did without having seen the OP, gotten a hx, and etc.

Wow. I guess that when you need to defend your behavior as a jerk that you'll try to BS your way through a discussion ...

My initial comments in this thread came hours AFTER the OP had already declared that s/he would see his/her family doctor ...

I was indeed offering an alternative hypothesis to the OP's query as to whether his/her metabolic rate was a factor.

So, THAT issue is moot & did not need to be reenforced ...

OR, is this thread & the remarks within it solely about YOU?

Again, I didn't say that the OP shouldn't see a doctor ... how you choose to misread what I write just shows that you need to get a grip on the greater reality beyond your parochial existence.

alfeng said:

Wow. I guess that when you need to defend your behavior as a jerk that you'll try to BS your way through a discussion ...

My initial comments in this thread came hours AFTER the OP had already declared that s/he would see his/her family doctor ...

I was indeed offering an alternative hypothesis to the OP's query as to whether his/her metabolic rate was a factor.

So, THAT issue is moot & did not need to be reenforced ...

OR, is this thread & the remarks within it solely about YOU?

Again, I didn't say that the OP shouldn't see a doctor ... how you choose to misread what I write just shows that you need to get a grip on the greater reality beyond your parochial existence.

Nice try, Feng, but slight of hand won't earn you respect.

alienator said:

Nice try, Feng, but slight of hand won't earn you respect.

Respect?

From YOU?!?

Gee. Wouldn't that be a Sign of the Apocalypse?!?

insane said:

Hey guys. I just started cycling long distances like 10-13km, and sometimes i get this throbbing headache while cycling. When i get off the bike, and sit down, immediately my vision blacks out, like blood rushing to my eyes or something. Any reason why, and is it linked to the fact that I have a high metabolic rate?

Extra info: I'm 19, 174cm tall, but due to my high metabolic rate, i weigh a frightening 40kg.

Your crazy cycling at that weight. You better see a "Doc" fast

DO see your doctor and in the meantime perhaps you might want to document (write some notes) about what other activities you participate in and what symptoms you have experienced to give the doctor more information.

My wife was an active volleyball player but had dizziness and blurry vision at the top of our local climb when she first started riding, maybe a few times in her first couple months. By the time she had her appointment with the specialist here it had all but cleared up. 1 year later and she now rides 200k in 8hrs in 90 degree heat and 90 percent humidity with no related symptoms whatsoever. So stay positive and try to make the most out of your consultation with the doc.