As much as 80 percent of people who contract the Zika virus will feel little to no symptoms.

For those who do, they may experience a week’s worth of low fever, rash, joint and muscle pain, and reddened eyes, among other symptoms. For those expectant moms who are pregnant while infected, however, the virus may lead to much more serious complications for their developing fetus, including microcephaly, or a smaller than healthy head and brain. Here's how Zika attacks the bodies of these children and other victims.

There’s still a lot we don’t understand about Zika’s capacity for destruction, but there are things we've figured out. First, the virus can sometimes reach the nervous system from the bloodstream, directly infecting the nerve cells nestled there. Most adult sufferers can take the bruising it inflicts and come out with little harm done, but a rare percentage don’t. These unfortunate patients may come down with Guillain-Barré Syndrome, a disorder that leads to muscle weakness, tingling leg sensations, and even temporary paralysis. Zika may even make it as far as the brain, triggering a massive swelling of the brain and other neurological symptoms. In these cases, Zika isn’t so much directly harming an individual as it’s goading the body's own immune system to go haywire and begin attacking the nervous system.

In fetuses, however, there’s evidence that the ZIka virus directly attacks fetal nerve cells and even interferes with the normal development of the brain’s structure, leading to microcephaly. Though we’re still not 100 percent sure, scientists believe that this type of damage can occur only in the earliest days of pregnancy, during the 1st trimester. Other scientists have speculated that Zika is more than capable of causing less visible damage to the fetus — the effects of which we may not see for years after birth.

The virus also appears to increase the risk for a miscarriage, though researchers are not certain why as of yet.