After really hard workouts I always get headaches???

Make sure you are fueling your workouts with Protein and Carbs. Headaches while working out means your body isnt getting enough fuel!

Also if you are on any kind of medication it could be caused by that.Personally if I was you I would go see a DR.

Do see a doctor - I think it's sensible to check it out.

In the meantime, maybe do a body check for muscular tension in your body. For instance, I often get a headache swimming, because of the way I hold my head and neck, producing a lot of tension in my neck. Sometimes I get the same from running, from kind of gritting my teeth and setting my muscles hard to 'push through' when the going is tough. I have to consciously relax these muscles as I'm exercising to help with this. Does that sound familiar to you?

and can scoliosis be linked with it at all?

It could be. The curvature can produce headaches *anyway*. Added stress with exercise might be contributing. I'd see your doc. If s/he thinks it's linked, maybe seeing a sports physio or a really good PT for a few sessions to work out how to avoid the pain might make sense?

This may sound really really strange, but when you get the headache, lick some salt. Like a tequila shot with out the lime and tequila. If that's your problem you will instantly start to feel the headache lessen. I used to get em all the time, and because you're sweating and eating healthier your sodium levels in your body might be low. I used to keep a few McDonalds packets in my locker when I was in high school for after practice for just that reason.

Is there anything that makes the headache better? Or do they just go away on their own? It could be from developing low blood sugar from exercising, so having protein before and after exercise might help.

As the other posters said, a trip to the doctor may be in order. Hope you figure it out!

Caveat: IANAFE and IANAD

The first question group of questions I'd ask: what kind of workouts are you doing? Length and intensity? Are you outside/inside Heat or comfortable temperatures?

Obviously a Doctor would be helpful. But until then, figure out if you're getting enough water?

You can make yourself into a guinea pig if you'd like, try changing one thing each time you work out (while keeping the workouts
similar otherwise).

Perhaps add another 600ml of water during the workout?

1.2 liters may seem like a lot, but if you have an extensive workout you could still find yourself dehydrated. I may be atypical but I have a 50oz camelbak, and 2 24 ounce water bottles and by the end of the workout, I'll have gone through all of that and had to stop just to refill one of the water bottles to finish. and even after all that I was still down a good 2 pounds before and after the workout.

As someone else pointed out, you could be 'bonking' or having a glycerine crash as well, a quick way to test that is to eat something about an hour before you work out. see if that helps

Good luck and keep us updated!

YOU ARE DRINKING WAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAY TOO MUCH WATER. You are depleting your body of electrolytes (Potassium, Chloride & Sodium) If you truly drink that amount of water, I am surprised you are just getting headaches! Seriously, you can die from this. You should max out at 9 - 8oz glasses a day!

Is there anything that makes the headache better? Or do they just go away on their own? It could be from developing low blood sugar from exercising, so having protein before and after exercise might help.

As the other posters said, a trip to the doctor may be in order. Hope you figure it out!

I usually have to sleep it off. And I have an appt but the closest one is not for than a month!

You may have exercise-induced headache or exercise-induced migraine. Google it~

I'm fair sure it is not due to dehydration as I drink usually about 2, 600ml bottles of water at the gym alone and then 8-10 glasses outside the gym.

I have scoliosis and depression. Could the scoliosis be linked in with this somehow?
Anyone know what could be causing this ??

Breathing wrong, Vasvalva maneuver, high blood pressure, there could be a myriad of issues that brings this on. Start with breathing and go from there. Make sure that you're blowing out on the hardest part of the exercise and breathing in on the easy.

YOU ARE DRINKING WAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAY TOO MUCH WATER. You are depleting your body of electrolytes (Potassium, Chloride & Sodium) If you truly drink that amount of water, I am surprised you are just getting headaches! Seriously, you can die from this. You should max out at 9 - 8oz glasses a day!

Can you provide resources, please? If I only drank that amount in the dry, dry climate I live in, I would be chronically dehydrated. Add exercise on top of that, and I would be sick with dehydration - headaches, etc. I have read that it is not so much about how much you drink, except everyone should get a minimum, but how quickly you drink it. This is from my own reading, mind you, but my understanding is that the kidneys can process an enormous amount of water daily, as long as it is taken in throughout the day and not an enormous amount at one time, and that if you are concerned you should replace your electrolytes.

Edit: I drink at least 10x8oz glasses a day, often closer to 12. So far, no issues. But of course that could be different with different people.

According to the original post, she is drinking more than double what you are drinking.
Here are a few sites for you to look into;

http://sportsmedicine.about.com/od/hydrationandfluid/a/Hyponatremia.htm
http://health.howstuffworks.com/diseases-conditions/death-dying/water-intoxication.htm
http://www.bettermedicine.com/article/electrolyte-imbalance
http://www.mayoclinic.com/health/hyponatremia/DS00974
http://www.scientificamerican.com/article.cfm?id=strange-but-true-drinking-too-much-water-can-kill
http://www.mayoclinic.com/health/water/NU00283

Your welcome.

Thank you for the resources, I will definitely read them.

Edit: I also drink 2-4 cups of tea a day, don't know how that factors in to my "water consumption," (just know my urine is generally nearly clear) but I'm always sipping on something in this heat. Seems like it might be needed to up water consumption beyond 9oz in dry climates, and that it could be done safely. But I will take a look at those resources to see what they have to say.