Does ventral hernia usually cause many symptoms?

No. Ventral hernias encompass a broad range of hernias of the front of the abdominal wall, including umbilical, epigastric, spigelian, and incisional hernias. Symptoms are primarily related to the size of the hole in the abdominal wall and what, if anything, is getting 'stuck' in them. While not all of these require repair, this determination is best made by a hernia surgeon.
No. Most ventral hernias are asymptomatic. If a loop of intestine becomes incarcerated in the hernia, however, you can develop nausea, vomitting, abdominal pain, and can become quite sick. Discuss your specific case with your doctor.
If you don't know .. If you don't have any symptoms you probably don't have to worry. Most hernias that are asymptomatic do not need to be .fixed. Symptoms such as cramps abdominal pain, nausea, bloating or a lump that bulges under your incision when u cough are possible symptoms of a hernia. See your doctor if concerned .