When Tori Foles, the wife of Philadelphia Eagles quarterback Nick Foles, started having symptoms of fatigue, nausea and dizziness, she brushed them off.

But after nearly fainting at a concert and passing out behind the wheel in July 2013, the then-23-year-old knew her symptoms were serious.

She saw several doctors that summer who told her that she probably had a virus, or was dealing with undiagnosed anxiety or depression.

After six weeks of multiple tests, Tori finally received a diagnosis of postural orthostatic tachycardia syndrome, or POTS, a malfunction of the autonomic nervous system, which controls functions such as heart rate and blood pressure.

In her blog, Tori, now 28, describes the struggle of getting a doctor to take her symptoms seriously and how she hopes to encourage other women, who are the ones mainly affected by this disease, to trust their gut if they believe something is wrong.

POTS is a condition characterized by too little blood returning to the heart when moving from a lying down to a standing up position (orthostatic intolerance).

Orthostatic intolerance induces lightheadedness or fainting that can be eased by lying back down.

In people with POTS, these symptoms are also accompanied by a rapid increase in heart rate, drop in blood pressure and trouble breathing.

For example, someone with POTS could lie down for 10 minutes and feel their heart racing the moment they get up.

POTS is a type of dysautonomia, which are disorders of the part of the nervous system that regulates blood pressure, heart rate, and breathing patterns.

The disorder affects between one and three million Americans, mostly women under age 35. The cause remains unknown but episodes may begin after a pregnancy, major surgery, trauma, or a viral illness.

It is common for POTS sufferers to go years without an answer as to what’s wrong with them. The largest POTS survey, conducted by Vanderbilt University and the University of Calgary, looked at more than 4,000 diagnosed POTS patients.

Researchers found that most people spent an average of four years and saw about seven doctors before receiving a diagnosis of POTS.

Tori detailed in her blog how it took visits to four different doctors to finally diagnose her. One cardiologist insisted the condition was all in her head.

‘I will never forget when he looked at me in his office and said: “You are young and healthy. You are in perfect condition. Have you looked into depression or anxiety?”‘ she wrote.

‘I was thinking, “Is this what depression feels like? Do you feel tired and do you nearly faint? Do you feel nauseous and sick?”‘

The POTS survey also found that, like Tori, more than 75 percent of patients were told their symptoms were psychological and a quarter said they were treated for a mental disorder before they received their proper diagnosis.

As her condition started to worsen, she visited another doctor and insisted on a thorough examination.

‘He had me stand up and took my vitals ‘ she wrote. ‘My heart rate went up by about 40 bpm (beats per minute). BINGO.

‘If your heart rate is increasing by more than 30 bpm upon standing, then you have POTS and your autonomic nervous system is not regulating things. It took one minute to figure out. It makes me mad just talking about it.’

There is no cure for POTS but many treat their condition by making lifestyle changes to help increase blood pressure and blood volume.

Such changes including adding extra salt to the diet and drinking more fluids.

Some may be prescribed thigh-high medical compression stockings, which push blood up from the legs to reduce POTS symptoms

Certain medications may be prescribed, such as fludrocortisone, which is a type of steroid, or midodrine, which helps treat low blood pressure.

Tori’s doctor told her to increase her salt intake and put her on fludrocortisone to help retain the salt and fluids in her body.

Both she and her husband consistently work to raise awareness about the disorder.

The couple met at the University of Arizona where Nick was the quarterback for the Arizona Wildcats football team and she was a setter for the volleyball team.

They were dating when Tori received her POTS diagnosis and, in fact, became engaged while she was at the Mayo Clinic.

‘It’s crazy, we spent a whole month at the Mayo Clinic,’ Nick told reporters days before the Super Bowl.

‘We got engaged at the Mayo Clinic, we got married at a courthouse two months later because we knew we were in for a run.

‘We’ve never had a wedding ceremony, we’ve never had a honeymoon, but…just to see her strength, and to see her determination and her health continue to improve.. it’s amazing. It gives me strength because I know she deals with it every single day.’