Blood in the saliva is usually caused by the following two conditions. The first condition is most commonly caused by chronic periodontitis, which often results in spontaneous bleeding of the gums, and blood in the saliva is found when spitting in the morning. The second condition may be gingival tumors, which are mainly found in women during pregnancy. Because of changes in hormone levels, even a small amount of tartar irritation can form a pseudotumor, and this pseudotumor is prone to bleeding.