After Areli Torres caught the coronavirus, the fever and headache disappeared in a few days, but she says it took seven months for Mexican doctors to correctly diagnose the debilitating long-term effects.
Her case illustrates the huge challenge that the country's already overwhelmed health system faces helping people with "long Covid" -- the symptoms that sometimes linger long after the infection.
Torres, a 31-year-old engineer, fell ill with the coronavirus last June but the worst of her initial symptoms lasted only four days.
She tested positive three times up to August but decided to try to return to her normal life.
A month after she was infected, however, parts of her body began to go numb.
Now, it is one of her legs that gives her the most discomfort.
"Everything's uncertain. Everything's been an ordeal. I've seen four doctors," Torres said.
The first doctor, from the Mexican Institute of Social Security (IMSS), concluded that it was anxiety and prescribed antidepressants.
Two private doctors, including a neurologist, agreed with that diagnosis.
Torres tried therapy, yoga and exercise but still "half her body was numb," she said.
- 'Be patient' -
It was in February that another doctor identified the problem as inflammation of the nervous system as a result of the coronavirus.
Among other things she was advised to "be patient," although by then she had already had to postpone her wedding.
At least 1.6 million people have survived Covid-19 and around 184,000 have died from it in Mexico, a country of 126 million, according to official figures.
Limited testing means that in reality, both figures are likely to be significantly higher.
There is no data on the number who are have suffered long-term effects.
In October, a senior health ministry official said that less than five percent of those who became seriously ill needed respiratory rehabilitation.
But doctors are increasingly taking the view that people who initially experience mild symptoms are also at risk of suffering from long Covid.
"It's not only those who were severely or critically ill, as we first thought, who will develop after-effects," said Maria Isabel Jaime, deputy head of the IMSS's physical medicine and rehabilitation unit, told AFP.
She said they were also seeing patients who develop after-effects a few weeks after overcoming a moderate illness.
Those symptoms include respiratory, gastrointestinal, kidney, liver and nervous system issues, as well as fatigue, muscle weakness, neurological disorders and anxiety.
The World Health Organization this week urged governments to make a priority of understanding the long-term effects of coronavirus infections.
About one in 10 Covid-19 sufferers remain unwell after 12 weeks, and many for much longer, the WHO said.
- 'Looking for answers' -
Some units of the IMSS and the National Institute of Respiratory Diseases (INER) offer pulmonary rehabilitation therapies, but they cannot help everyone who needs it.
The Mexican social security system has about 20 million members and gives other forms of medical cover to another eight million people.
Leftist President Andres Manuel Lopez Obrador says that his government inherited a health system weakened by years of neglect.
At the start of the pandemic, Mexico had a shortage of 200,000 doctors and 300,000 nurses, according to official figures, so the government went on a hiring spree.
It also scrambled to adapt almost a thousand hospitals to care for Covid-19 patients, suspended transplant operations for several months, and generally reduced care for patients with other serious conditions.
The government says that 75 billion pesos ($3.6 billion) has been invested in the sector during the crisis.
Even so, the infrastructure to care for patients with long Covid "is probably not enough to meet all the demand," Jose Luis Alomia, the health ministry's director of epidemiology, acknowledged in December.
For long haulers like Torres, there are still a lot of unknowns about why the illness that she thought she had beaten, refuses to go away.
"There's a lot of ignorance about the consequences or persistent symptoms of Covid-19. I'm still looking for answers," she said.